I have been working with my dad on his cancer treatment since last year. My interest in the topic has only peaked ever since.
(Disclaimer- I am an engineer and not a microbiologist/doctor)
Mutations and wrong copying of genome happens all the time in the body and some enzyme has the job of correcting the mutated genes so it doesn’t get into the system. Level 2 defence is T cells killing it as identified as foreign body.
Thing that baffles me is that I see most work happening to eliminate tumor. To me it sounds a tough problem given the permutation and combination of mutation— roughly few trillions.
But I was curious if there is working happening on L1 defence — fixing the enzyme that fixes the wrong copy paste mechanism. Or making the enzyme get more efficient and powerful. Is that line of thought even valid?
Our L1 defense is actually incredibly good. A human will undergo about 10^16 cell divisions over the course of their lifetime. Around 10^3 to 10^6 of those divisions will result in a mutation that gets past the L1 defenses and need to be eliminated by the T cells. It's not generally easy to make dramatic improvements to something with a 99.9999999% success rate.
The immune system is pretty good too, which means any given improvement to the replication system is, all else being equal, probably going to prevent mutations the T cells would already handle. If you need to do the research to figure out what's getting past the immune system anyways, and improving the immune system is lower hanging fruit, it's the logical place to start.
Aren't the elephants and whales orders of magnitude better than us at that though (they have roughly as many cancer as we do, but with respectively x100 and x1000 times as many cells.
Or is it the second layer that works better for them?
Different species do have different levels of protection, and different lineages tend to employ different methods of protection. For example elephants have numerous duplicates of cancer suppression genes, whereas naked mole rats produce a variant of hyaluronan which prevents tumor formation. When compared to other great apes, Humans seem to be worse at both layers of defense.
It's worth noting though that humans also have much higher levels of exposure to many carcinogens than most animals, and we screen for cancers at a much greater rate for humans, so just because a species has lower cancer rates doesn't necessarily mean their cancer defenses are better.
also, Elephants have a much higher copy number of a gene called p53/ It codes a protein that acts to force suicide in cells that have damaged DNA (think from UV light, cigarette smoke, age, etc). In cancer this is a common 'early' mutation that allows collection of further mutation and progession towards cancer. In having many more copies of p53, it makes it less likely the p53 function will be eliminated
I am not sure how much consensus there is around it but this is so cool I have to repeat it sorry: Whales and elephants do develop cancers but since those cancers also have mutations, well their cancers have cancers and overall the cancers are never able to grow big enough to threaten the whole organism.
The idea that tumors develop their own tumors, suppressing cancer is known as the Hypertumor Hypothesis and, while it works in computer models, there isn't actually any evidence backing it up.
The hypothesis doesn't really resolve Peto's paradox, the observation that cancer rates don't scale directly with the number of cells in an organism. Not only do large organisms like whales get fewer cancers per cell division, small animals like mice get more cancers per cell division, which can not really be explained by a threshold beyond which hypertumors suppress tumors. The actual evidence suggests organisms just evolve whatever level of cancer resistance they need to have low odds of dying of cancer before something else kills them.
That being said, the main observation underpinning Peto's paradox was actually just due to lack of good data. Over the years much more data has been collected from animal autopsies and it turns out that big animals do get cancer and cancer rates actually do scale with body size, just different species have varying levels of cancer protection, with the levels of protection being similar in closely related species of different sizes.
This is a fascinating niche of evolutionary biology that I have worked in for a while. The short answer is that yes, as far as we can tell all organisms evolve increasingly more efficient replication machinery, however at some point the strength of selection is no longer powerful enough to overcome the strength of genetic drift and some degree of error rate persists. As far as we can tell it seems like population size governs where this balance ends up such that small populations have high mutation rates and large populations have reduced mutation rates. Michael Lynch coined the term drift barrier hypothesis to describe this phenomenon. https://pubmed.ncbi.nlm.nih.gov/23077252/
Yes, but note the mutation rate of germline cells - that are passed to your offspring and hence influence evolution - is estimated to be two orders of magnitude lower than other (somatic) cells.
Not necessarily if it had recombination (as in sexual reproduction), but as far as I understand, yes, you’d probably get fewer novel alleles/coding sequences of DNA generated per organism replication
It starts with mutations (sometimes accelerated by mutagens (smoke, alcohol, etc) or inflammation (viruses, infections, etc) or just chance (things like asbestos up the division rate by constant physical damage and thus up the probability or an error in copying).
But there is much more to it. This is a nice paper for an overview: Hallmarks of Cancer (tng) [0]. It (among others) adds the very important and for years underestimated role of the immune system to the original 2000 paper.
Would sports also increase the rate of division? Bodybuilding for example you intentionally make micro tears in muscles to get them to repair and grow (lay person, apologies for the mistakes)
The problem is that many things that reduce the probability of cancer increase the probability of other diseases.
Therefore there is no good solution for this.
For instance, some studies have demonstrated that certain kinds of malnutrition, i.e. the consumption of inadequate amounts of protein and/or with bad amino-acid profile, inhibited the development of tumors caused by carcinogen agents (in rats and mice). This was not really surprising, because tumors grow faster than the rest of the body so they need to synthesize more proteins. If they are starved, they grow slowly and the immune system has time to react and to eliminate the incipient tumors early enough.
Despite this, starving yourself in the hope to avoid cancer would be a very bad idea. While the probability of cancer is lowered, the probabilities of low resistance to infectious diseases or of muscular weakness leading to falling and breaking some limb, or of cardio-vascular diseases, become higher.
Hmm, I'm a molecular biologist, not an expert at this particularly, what I do know is that damage of muscle fiber may not be necessarily mean new cell growth and thus extra DNA replication. The growth of the muscle cell certainly does.
Exercise is good for the immune system, this helps clear cancer, helps stay away from inflammation (ie auto-immune diseases). Where as a sedentary life style a poor diet will promote this.
But indeed for some things/behaviors, the relation the cancer may be complex.
L2 is being prioritized because our L1 defences are already very good. We are a long-lived species, and our natural ability to fix errors is so good that it is hard to improve upon. Maybe the long-lived tortoises or whales can do it better, maybe. But we have "several nines of reliability" there.
OTOH our L2 isn't that good, mammals in general (with some notable exceptions such as bats, whales and naked mole rats) are prone to cancer in their older age. There probably is a lot of relatively low-hanging fruit there.
If you think about it - individual cells aren't very precious and if some of them gets FUBARed by something (a virus, radiation or chemical insult), it is better to whack it and reuse the proteins to build a new one, if possible, instead of wasting time and resources on reconstruction of a total wreck.
Which also means that some research into replenishment of stem cells is necessary - and this is, IMHO, the really underfunded part of the whole thing. We lose a lot of stem cells as we age. Maybe we don't have to.
While cancer is caused by mutations in the genome, these mutations in turn produce the unifying property of cancer: unchecked cell replication.
Most cell types have systems to safely manage replication. Broadly, there are gas pedals (oncogenes) and brakes (tumor suppressors). A classic oncogene is something like RAS, which activates a signaling cascacde and stimulates progression through the cell cycle. A canonical tumor suppressor is something like TP53, the most frequently mutated gene in cancer, which senses various cellular stresses and induces apoptosis or senescence.
Most cancer genomes are more complicated than individual point mutations (SNPs), insertions, or deletions. There are copy number alterations, where you have > or < 2 copies of a genomic region or chromosome, large scale genomic rearrangements, metabolism changes, and extrachromosomal DNA. There is a series on the hallmarks of cancer which is a useful overview [1].
All of the mechanisms that intrinsically regulate cell growth would fall under your "L1 defense". Unfortunately, the idea of reversing somatic point mutations is likely to be a challenging approach to treating cancer given the current state of technology.
First, for the reasons above, cancer is often multifactorial and it would be difficult to identify a single driver that would effectively cure the disease if corrected. Second, we don't have currently delivery or in vivo base editing technology that is sensitive or specific enough to cure cancer by this means. There are gene therapies like zolgensma[2] which act to introduce a working episomal (not replacing the damaged version in the genome) copy of the gene responsible for SMA. There are also in vivo cell therapies like CAR T which attempt to introduce a transgene that encodes for an anti-cancer effector on T cells. These sorts of approaches may give some insight into the current state of art in this field.
Edit: also I should note that the genes involved in DNA repair (PARP, BRACA1/2, MSH2, MLH1, etc) are frequently mutated in cancers and therapeutically relevant. There are drugs that target them, sometimes rather successfully (e.g. PARP inhibitors). But the mechanisms of action for these therapies are more complicated than outright correcting the somatic mutations.
While I can't speak to whether there are enzymes for the proper copy/paste I do have a set of random cancer related bits I've picked up over the years.
There are some basic, well-known nutritional interventions that are generally important/critical for DNA repair processes. The 2 main ones are Vitamin D and Magnesium. Ensuring adequate amount of these tend to be helpful (most folks aren't getting enough sun and greens).
Other than that, a steady and adequate source of the substrates seems to be important: ie protein (nitrogen), and phosphates.
One of the interesting bits about some cancer cells is that while they simply haven't gone through apoptosis, physical sheer stress incurred from physical activity (exercise) can cause cancer cells that travel beyond the tumor point (before it becomes metastatic) to finally self destruct.
It seems important to me that the best strategy for cancer is the compounding of many different strategies that optimize the body's innate defenses to run optimally.
It does seem that ketogenic diets may have adjuvant properties, but there is yet to be a clinical trial that demonstrates it, so it's basically stuck in paper and R&D stages as to whether being in a ketogenic state can be one of the last areas that may help cancer patients extend lifetime from say 1 year to 2 years.
I know this is a bit off topic, but have you ever thought about why steroids and other forms of doping are not a free lunch? Why can't we just inject an external chemical to boost our strength for free without any side effects?
If steroids worked, everyone would be constantly injecting them. It would be like drinking coffee.
And that is the reason why steroid injections are harmful. If there is a free lunch, the human body will simply produce the optimal amount of steroids on its own until the Pareto frontier is reached and a tradeoff needs to be made.
Where does the body get the materials to form the steroids? From your diet. So the primary intervention is always a healthy diet and an active lifestyle. You know, the boring things that parents drill into their children.
It's valid but "medicine" that has only upsides and no downsides isn't medicine, it's diet.
I don't know the specifics of efforts to "repair" DNA replication repair (if you get my drift), but I suspect there is some effort in that area.
There definitely are efforts to correct enzymes involved in tumor-suppression (p53 is probably the best known tumor suppressor protein). e.g., here's a study on a small molecule designed to correct mutated p53 https://pmc.ncbi.nlm.nih.gov/articles/PMC8099409/
Also not a doctor or microbiologist, but just wanted to share my layman’s guess on why fixing enzymes will not completely solve the issue: there’s 2 strands of DNA and to fix the broken (mutated) strand you need to have one correct template strand intact so you know what it should be fixed into. It could be the nucleotides swapped places between strands or are deleted completely or otherwise both mutated, which would mean any repair will not revert the sequence to what it used to be.
The other comments so far are probably more informed.
Cancer sucks, I wish all the best towards a recovery.
You’d also have to ‘fix’ DNA: unless we can re-engineer a bunch of key enzymes and then re-encode the entire genome (or maybe key parts) with forward error correction without breaking everything else, it might work. You might also break evolution to some degree by making random point mutations less likely.
But what I learned so far is that as soon as you’d attempt something like this in bacteria, the fitness advantage from an evolutionary standpoint is negligible compared to the efficiency loss introduced by FEC, so your colony would get outcompeted by other bacteria unless there is a niche your resistant bacteria survive in (high radiation environments?). The efficiency loss induced ‘disadvantages’ would probably be less pronounced in mammals though - If (big if) you manage to not also break anything essential in the wonderful yet surprisingly efficient Rube Goldberg machine that is life.
What I meant was there are collection of genes responsible for error correction. If there is a failure in duplication then these genes have not done their job.
Thought experiment, again as a layman, was to see if these genes responsible for error correction at the base level can be fixed or bolstered and that will act like a cancer vaccine. But looks like from other comments that this is even more harder!
> fixing the enzyme that fixes the wrong copy paste mechanism
The DNA fidelity issues contribute to only some cancers. Many are caused by mutations due to environmental damage and some are caused by viruses. The point is, there's a huge variety of reasons for developing cancer. So you cover more cases by developing treatments that are more "universal".
> But I was curious if there is working happening on L1 defence — fixing the enzyme that fixes the wrong copy paste mechanism. Or making the enzyme get more efficient and powerful. Is that line of thought even valid?
Mutations in general are not the defining quality of cancer. It's mutations in these very L1 safeguards. There are several such safeguards and a cell needs several mutations in those to become malignant. Eg. https://en.wikipedia.org/wiki/P53
Correcting genes only works in certain conditions (e.g. limited single strand breaks), in a narrow time frame during cell division, safeguards rather trigger cell suicide, or if that fails they mark the cell for destruction by immune cells. A cell can't fix DNA which made it through cell division once, because it got nothing to proof-read against.
After the safeguards are gone, everything goes and genetic diversity increases quickly within each tumor. This diversity is what's making cancer treatment hard. At some point there won't be a shared vulnerability in all malignant cells. The repair mechanisms are working in favor of the cancer now. For example, with radiation therapy you preferably want to induce DNA double strand breaks, because cancer cells can't repair those. Otherwise you need to increase the radical burden enough to overwhelm repair, but migrating radicals may damage distant cells, too.
I presume you could hypothetically inject mRNA of a working safeguard gene (eg. P53) into all cells (at some point cancer cells can't be selected exclusively, since they lost identifying marks and present as stem cells), so the functional enzyme or transcription factor is forced to be built inside. I am sure people are trying this right now. However, the inner workings of cells on a molecular level are insanely complex and our understanding is only scratching the surface. As with P53, you have a transcription factor, which means it's modifying gene expressions elsewhere. It's only a small part of a complex regulatory cascade. I doubt there is a safeguard target, which can easily be injected without considering the precise timing and environment within that safeguard cascade in the cell. Of course, the rest of the safeguard system needs to be present in the cell to begin with. Mind you, you don't want to cause cell suicide in healthy cells, so you want to restore the function of whole selective complex.
Then there is the question of delivery. Can you deliver eg. the mRNA to every cell without raising suspicion of the immune system? With the COVID vaccine, the enabling breakthrough was the delivery vehicle, not as much the mRNA part. Can you even reach the cancer cells at all? Cancer cells are frequently cloaked, shadowed or cut of by senescent, or necrotic cells, or acquired unique ways of metabolic adaptations. A bit similar to bacterial persistence, like M. tuberculosis, which can evade bodily and chemical defenses for decades.
The take-away: Life is complex beyond comprehension! Despite simplifications taught in schools and reductionist zeitgeist, we actually know very, very little about what's going on in genetics and molecular biology, most medical knowledge is empiric guessing instead of explanatory understanding.
The catch is that there are thousands of promising therapies in animal models/pre-human testing. A very very tiny fraction of them will ever make it to market for a variety of both good and not-good reasons.
Prevalence of the disease - if it only impacts 1/100 million, going to be hard to ever find sufficient patient population to test and recoup your investment.
Existing quality of treatments - if there are already efficacious drugs on the market - how sure are you that this new therapy will be best in class? Only being as good as the status quo is not an ideal competitive position. Conversely, if there is an unmet need because a disease is so lethal/debilitating, regulatory agencies can give latitude in approvals.
Likelihood patient compliance - if it is the most effective drug in the world, but requires intravenous infusion six times a day - nobody is going to adhere to that. GLP drugs are effective, but there is a needle-phobia that is preventing patients getting on board with the idea. Which is why there is an arms race for the first company to develop an oral version.
Toxicity - all chemicals are poisonous. Yet some have a lower therapeutic window than others. If you drug does what it should, but if you take 2x as much and it gives you a heart arrhythmia that is going to be a tough approval for anything but the most deadly conditions.
Yes, you can. The problem with testing is that a candidate treatment may make things worse for patients, not that it may improve things.
If your treatment works, that’s an improvement of what you had before. Once you know that, you can treat all patients. For some, that will be too late, but without your tests, it would be too late for them, too.
If your treatment doesn’t do anything at all, it keeps things the same, but the patients in the test group likely will have had some inconveniences (having to visit a doctor, getting an injection, etc), so you shouldn’t do the test.
If your treatment makes things worse, you of course shouldn’t do the test.
Problem is that you typically only can only know in hindsight which of these applies.
So, you think carefully on whether a treatment could fall in category 3, and, if so, first do it on a group of patients who consent to be Guinea pigs and, often, are already terminally ill, as any negative outcomes will cause less harm to such patients.
Then, as soon as during the test your stats tell the drug does or doesn’t work, you stop the test and either treat all patients or stop treating the test subjects.
I guess I'm not being clear. Are these examples of "good" or "bad" reasons to not go to market? I assume "good"? If so, what would be an example of "bad"? Or vice versa if your meaning was opposite.
I responded below already but since writing that, I've come up with a few more great bad reasons not to bring a drug to market (sorry for the parseability of that one...)
Best bad reason: it would cannibalize an inferior drug currently in your portfolio that's still under patent protection.
I think this behavior is at the far "evil" end of the spectrum of behaviors that drug developers systematically engage in (which I believe is far more banal + less evil than what they're accused of), but it does happen and it's a really nasty
Where it gets especially nasty is when companies buy drugs in development or pre-development from other companies in order to squash (or at least delay) a potentially competitive asset before it reaches the market.
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Another great bad reason, but mostly applies to devices/procedures: the device/procedure is fantastic but for various structural reasons outside of the control of the device/procedure developer, there is insufficient incentive for healthcare providers to actually deploy said device/procedure.
A trivial example would be a pacemaker that requires fewer leads than the competitors and has fewer complications. Great for patients, but potentially totally uninteresting to the electrophysiologists who install it and would get paid less due to the less complex procedure.
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Best good reasons all fall under: making a therapy is unfathomably difficult and most efforts are destined to fail OR (separately) proving a therapy works is unfathomably expensive and most efforts can't produce a positive ROI after that process.
Ultimately most of these decisions come down to economics and not mustache twirling villains. The banality of evil.
Simplest "bad" reasons are the wealth of the patients. Malaria, river blindness, guinea worm, etc are terrible diseases that mostly impact poor people out of sight from Western eyes. Spending $X billion developing a drug for a population that can barely afford to feed themselves is not going to make a financial return on investment.
Well, it would for those countries, but yes, it's not sensible for a private business with no guaranteed source of funding. If they did develop it and no one paid the PR would be even worse.
I'm not sure that is necessary a bad reason. You need to factor in a lot of concerns to determine what "too expensive" means.
But if you are going to spend billions of dollars to develop a drug that only treats about 2 people a year it is likely too expensive even if it is 100% effective. That money would be better spent on treatments that have wider applicability.
Of course this is not simple to measure. Costs aren't known upfront and the research may end up proving invaluable to more widely applicable treatments.
So it is a judgment call and not necessarily a bad reason.
Agreed it isn't necessarily a bad reason. In some cases it's a good reason for failure (like the one you describe).
In other cases it's a bad reason for failure: it's also incredibly expensive to prove your drug works even if it does work for a lot of people.
That's bad! It'd be better if it were cheaper.
Actually counterintuitively, due to a weird drug approval and payor reimbursement policy arbitrage, pharma companies are highly incentivized to produce drugs for tiny populations.
One of my hobby horses is railing against this specific dynamic.
A lot of potential treatments are too easily available and can't be patented. If a big pharma company can't make massive profit from it, they won't bother bringing it to market. Consider that a not-good reason.
Other treatments may eventually prove to have too many serious negative side effects. That's a good reason to abandon them.
> A lot of potential treatments are too easily available and can't be patented.
This isn’t really an obstacle, at least not as much as it’s made out to be.
There are numerous examples of drugs being brought to market at high prices despite having been generic compounds. Even old drugs can be brought back at $1000/month or more at different doses or delivery mechanisms.
One example: Doxepin is an old antidepressant that is extremely cheap. It was recently re-certified for sleep at lower doses and reintroduced at low doses at a much higher price, despite being “off patent”.
This happens all the time. The drug companies aren’t actually abandoning usable treatments due to patent issues as much as journalists have claimed. If they couldn’t, for some reason, find a way to charge for it they could still use it as a basis for finding an improved relayed compound with more targeted effects, better pharmacokinetics, etc.
They’re not just dropping promising treatments anywhere if there’s a market for them.
About Doxepin. As many seniors do, I also suffer from extreme inability to stay asleep at night. I have trialed through all the known prescription and non prescription possibilities, only eszopiclone and baclofen seem to show some promise, however, eszopiclone is DEA listed, requires higher and higher doses, and if I take it more than say 2 weeks, it has rather serious side effects attempting to withdraw, addictive, serious anxiety, trying to wean oneself off it. Doxepin is prescribed as an antidepressant in large doses, one of the most potent H1 histamine antagonists known. The H1 system in our bodies promotes wakefulness. In very low doses, doxepin acts against the H1 to promote sleep. To avoid the upcharges of low dose doxepin, I am prescribed the high dose version, which I have to break the capsules to administer about 5 to 10 mg. placed in an empty gelatin capsule (it's bitter). It really works well, however you are fairly tired and useless the next day.
Why would a China or India care if it were a viable treatment? Unless a country wants to use their population as lab rats, it takes money and scientists to actually confirm a treatment is safe and effective.
This made me think of the "Institute for one world health" . It came out as a non-profit pharmaceutical company in the mid 2000's. Victoria Hale was the founder-it got her a MacArthur fellowship. It is focuses(focused?) on global health and populations underserved by for-profit models. I think they successfully developed a treatment for leishmaniasis. it's an adorable model and should be pushed but as usual it seems like the philantropy money is limiting.
In the early 2010s I had a couple friends working at a biotech startup with a moonshot cancer cure. They had amazing results in animal testing, and had raised just enough funding to do a first human trial on a terminal patient.
That patient was hit and killed by a car two days after finishing their treatment.
Along with the CEO's stubborn refusal to give up any more equity in the company, they went under, and the world will never know if that treatment worked.
From what I saw, there are very few experimental therapies that claim 100% efficacy, no side effect, no patent on complex engineering process to produce the drug.
I agree with GP that it is very notable.
I mean if it works on humans, which is not a stretch, colorectal cancer is done. It's huge.
Yes there are few that claim 100% efficacy and no side effect at this stage, but there are far, far, far fewer who make it to human availability.
I wouldn't describe it working in humans as "a stretch" per se. I'm not identifying a specific reason it shouldn't work in humans. I'm just saying that's true of thousands and thousands of really great looking treatments (per year!) that, nonetheless, end up not working in humans, or not being convincing enough to even warrant putting them in humans once.
If it is the case that there are such treatments (easy to produce, 100% efficacy, no side effect) that cure fairly common deadly disease such as colorectal cancer in mice, and that never make it to human trial, there is something seriously broken about medical research...
It's useful as a very early test. They used a shotgun approach, they tested 9 bacterias and 1 of them was suspenseful. At least it was suspenseful for 2 weeks, until the study ended. It's very difficult to extrapolate that to the 5 year survival rate in humans.
Very small sample size and only in mice. Most experimental treatments don't make it to the clinic, and this could be another in a long list of exciting early results that don't lead to anything.
However...
These results seem too good to be true, but the paper actually seems pretty good. There have been other attempts to use anaerobic bacteria to treat cancer (as solid tumors tend to be hypoxic environments), this is the first I've seen that interacts with PD-1/PD-L1 pathway. This is the most promising cancer treatment I've seen in quite a while.
Maybe we can be cautiously optimistic!
It looks like they screened 45 strains of bacteria to find 9 that passed their safety tests, and then only one of those had a 100-percent response. The sample size is also small: 5/5 sounds a lot less impressive than 100%. I'd expect the true response rate to be substantially lower ("winner's curse").
The bar for an acceptable side effect profile in an FDA-approved drug would also be a lot higher than "five genetically near-identical mice did not show evidence of pathology in a single study."
I'm not saying this work is bad (skimming, it seems fine for what it is, though haven't read in detail), but it's quite preliminary if we're talking about developing a medical treatment that could eventually be deployed in humans. There's a reason it ended up in a mid-tier microbiome journal.
I hesitate to link directly to a single podcast dealer, but if you search for Dave Ricks, CEO of Eli Lilly's podcast with Stripe brothers, there's some alpha in there.
A few years ago we also had 100% effective medication with zero side effects. Now birth rates are down, mortality up, and young people misteriosly die from cancer and hearth attacks.
Interesting article, but in the full paper their key figure (Fig 2) shows their treatment group of n=3 mice completely responded to the bacterial treatment, but their methods say they treated n=5 mice? Could be an honest mistake but that’s a little concerning for data manipulation.
Also agree that using a PD-L1 mab feels like it’s for show especially considering the cancer model they’re using (Colon-26) was shown to be substantially less responsive to PD-L1 inhibitors…
Still the idea is beautiful. Since tumors are oxygen-deficient and suppress the immune response, anaerobic bacteria would proliferate there, and wreak havoc, while in the healthy parts of the organism they would be rapidly eliminated. Additionally, since the bacteria accumulate in the tumor, and the immune system has just responded to their invasion, T-cells will flock to the tumor, destroying what remains of it in due course.
As they say, "the fame of a mathematician is measured by the number of poor papers", because pioneering works are often awkward, treading completely unknown ground. Maybe the same applies to biology sometimes?
I'm untrained in this area but it sounds like similar ideas I heard of in the last decade where injected tumor with virus (polio?) that quickly kills the tumor but then is easily cured in the rest of the body since we have solutions to them. Is this a similar situation?
Figures 2 and 3 seem to be different experiments, with n=3 and n=5, respectively. Both showed 100% survival. Obviously very small sample sizes, but still promising.
This segment about the mechanism is simple and very profound. I wonder if any cancer researchers here could comment on its universality across various types of cancers:
"Tumor-Specific Accumulation Mechanism
E. americana selectively accumulates in tumor tissues with zero colonization in normal organs. This remarkable tumor specificity arises from multiple synergistic mechanisms:
Hypoxic Environment: The characteristic hypoxia of tumor tissues promotes anaerobic bacterial proliferation
Immunosuppressive Environment: CD47 protein expressed by cancer cells creates local immunosuppression, forming a permissive niche for bacterial survival
Abnormal Vascular Structure: Tumor vessels are leaky, facilitating bacterial extravasation
Metabolic Abnormalities: Tumor-specific metabolites support selective bacterial growth
Excellent Safety Profile
Comprehensive safety evaluation revealed that E. americana demonstrates:
I have never once seen a promising cancer treatment I've heard of on the news help people. You hear about the breakthrough treatments all the time, but when people get cancer, all you ever hear about is people getting chemotherapy and radiation. Same old scary shit.
Well, I guess Leukemia has been somewhat cured I heard, so that's pretty huge. When I was a kid it was a death sentence IIRC.
I'm not a doctor, but in some fairness, I think there has been a lot of progress in chemotherapy and radiation. "Increasing 5-year-survivability by 0.5%" doesn't make a fun sexy headline, but that's still an achievement that required a lot of hard work and enough of those happening still adds up.
I agree with your overall point though; it's a little annoying that every few weeks we hear about a new experiment that seems to indicate that we'll have a radically new and effective form of treatment for cancer only for it to never materialize.
"Cancer" is a term that covers a lot of diseases. So there is a lot of research going into a lot of different things, and hence lots of announcements.
"Chemotherapy" again is a loaded term covering a lot of different drugs, drug combinations, protocols and so on. So yeah, a lot of cancer treatment us "chemo" - but today's chemo is far removed from 2000 chemo.
5 year survivability has increased tremendously over the last decades. We're not talking 0.5% here, breast cancer for example has gone from 72% to 93%. Early detection of prostrate cancer has near 100% survivability.
But you're right, improving survivability doesn't make for sexy headlines. Yes there's a social media appetite for "breakthroughs", but the underlying "boring" stuff is doing well, and getting better all the time. It's just not "news".
My mom died of cancer and had to suffer through chemo. It was in the early 2000s, so I'm curious to know if you know anything about these new chemos and what makes them different.
My condolences for your loss. Discussing things in general terms,while having a lived experience must be painful.
There are different cancers, different stages different, different chemos, and of course different people.
Ultimately individual experiences of chemo run the whole gauntlet. At one end it can be little more than a bit of fatigue, at the other end a horrendous nightmare.
Yes, chemo has, as it's goal, a poison function. It sets out to poison you, hopefully killing the cancer first. It's never going to be the "fun" part of treatment.
I'm not a Dr, much less a medical historian. I would be ill equipped to quote specific drugs or dosages. Outcomes however are easily Googled, and those don't seem to be controversial.
I get that improved statistics don't make individual loss any easier.
* Many breakthroughs from the first research stages never make it into medical application.
* Many breakthroughs are touted as some kind of "novel treatment", but when they get into the hands of the doctor, they talk about it as chemotherapy, because it kills cancer cells. So you might not even notice that you're getting something novel.
* Many breakthroughs take decades until they actually land in mainstream treatment.
* Many breakthroughs are specific to some kinds of cancer.
That said, in most developed countries, survival rates/times for cancer have been steadily improving for decades.
It's a bit like with solar cell and battery tech breakthroughs: you hear about them all the time, but it takes 20 to 30 years until they make it to production. But both have been improving steadily for an impressively long time.
Yes, you only hear about the initial breakthrough. The regular news doesn't report the trials unless things go spectacularly wrong. And you don't hear about the successes using the therapy on patients where traditional treatments didn't work. And you don't hear about the treatments successful enough that they replace the traditional treatments. But they are there, being used and saving lives. A family member's prostate cancer metastasized after 20 years of hormone therapy, they refused chemotherapy, and had their life saved by radioligand therapy, a treatment not available just months earlier. No side effects beyond a dry mouth, and now off the more debilitating hormone treatments.
AIDS has been treatable for a few decades, with good progression getting it to developing world and some towards a cure. That said, some of this recent progress has been impeded due to differing beliefs of some current governmental regulatory and research leadership, and beliefs that infectious disease treatments and vaccines are not needed for most people that are 'healty'.
So maybe I am too much a layperson here, but even without any direct therapetutic effects, it is pretty remarkable to have an easily scalable mechanism to get self-replicating agents into tumors, but nowhere else, is it not?
Yes it is amazing! Solid tumors tend to be poorly oxygenated, as they don't have a good network of blood vessels to supply them. The bacteria in these experiments can only live in low oxygen environments, so they will multiply in the tumor and die in any other part of the body they end up in. It's a clever idea, hopefully it will be successful.
Even lay-er person, but maybe the specificity is not that impressive in mice? Perhaps when you scale to more complex animals it is inevitable to see false positives (detrimental effects to healthy cells)?
Who knows how much knowledge we eradicated due to not bothering with climate change and just letting species go extinct.
Thankfully these were still here for this discovery.
Sorry, as someone in this field, this is bullshit. It is in mice.
Several things trigger my bullshit meter. Quote:
"This dramatically surpasses the therapeutic efficacy of current standard treatments, including immune checkpoint inhibitors (anti-PD-L1 antibody) and liposomal doxorubicin (chemotherapy agents)"
PD-L1 monoclonal antibodies are only effective against cancers that are, you guessed it, PD-L1 positive. At high percentages, ranging from 1 to 50%. Are these authors even familiar with the state of the art when it comes to cancer medications? Mouse tumors do not equate to people tumors. Many tumor types are not PD-l1 positive.
Doxy is an ancient SOC chemo.
This is a nothing burger.
Give me phase II/III clinical trials, and then let me know what their PFS/OS was after 5 years. and what the medians were at 3- and 5-years. Also, ORR and CR and needed.
CAR-T is ahead of the game, and will be the ultimate winner here as it grows to scale.
In my dad’s case- he had gastric melonama. We surgically removed it and as consolidation We administered pd-L1 Immune checkpoint inhibitor. Melonama recurred again in 6 months time. This time in esophagus.
As an engineer I think all drugs tested and efficacies studied are on statistically not so significant data points. Given the permutations and combinations far exceed the clinical trials available and hence everything post clinical trial is also just an extended trial.
Wonder How to fix this? I am assuming heLa cells etc are also not the right test setup to have better test results.
Keytruda, pembrolizumab, (what he probably received) can only do so much. If it was in his GI tract it was also elsewhere in multiple places. The PD-L1 drugs at this point have more than 400k patients treated, with decent efficacy. I'm sorry for your loss. If his melanoma had metastasized to his GI tract it was too late for anything except palliative care.
This drug has been used in a huge number of patients for more than 11 years; the next gen of drugs is currently being used. I'm sorry for my curt style of writing, but - people like your father have helped pave the way for that next generation of drugs by constraining clinical trial designs.
Nivumolab was the drug administered in adjuvant setting.
Maybe you are right that 400k patient with decent efficacy - however pegged chances are about 70-80% and not 100. So my point is can there be a better test bench to try and inch closer to a better efficacy?
For example - if hela cells can be used for trials — can there be the cultured tissue be used instead of mice as day 1?
Also curious — how did the scientist decide on using a specific cell/protein to be used for checking if this is producing results. Is it a hunch or science ?
Seems like a very interesting approach, even if it’s early stage.
> Many tumor types are not PD-l1 positive.
> Doxy is an ancient SOC chemo. This is a nothing burger.
Meh the research didn’t say those were state of the art, but that they were “common” treatments. In other words a baseline for a presumably cheap and well studied animal surrogate.
> CAR-T is ahead of the game, and will be the ultimate winner here as it grows to scale.
Last I read up on it last year CAR-T treatments struggled with solid mass tumors.
Many cancers don’t have unique proteins for CAR-T to target (similar to the pd-l1 issue).
Then CAR-T struggles getting the modified T cells into the solid mass tumors en masse. Interestingly this approach actually makes use of the tumor environment rather than be hindered by it.
> Sorry, as someone in this field, this is bullshit. It is in mice.
Nice to hear an expert opinion. Let's hope your comment goes back to black. I have a lot of question!
> This is a nothing burger.
Is it enough for a bread-mayo-bread sandwich? Lettuce?
IIUC the bacteria makes the cancer disappear for two weeks, until they end the study and kill the mice. (IIUC this is timeline is usual for very early studies.) They tried other bacterias and one of them made the cancer disappear for a few days, so I'm worried about the long time efficiency of this method.
Is injecting the bacterias a second time as efficient as the first time, or the inmune system kills the bacteria before they hurt the cancer?
What happen in case of metastasis? Each one must be injected with the bacterias or they will jump and make all of them disappear?
Does the bacteria infect other organs and kill you? Is there a good antibiotic in case the bacteria cause problems?
They used cancers that were 200mm3 (i.e. like a sphere of 7mm = 1/4 inch). What happens in bigger cancers? Does bigger cancer have better irrigation and make it more difficult for the bacteria to survive? What happens to tiny hidden metastasis (that probably still have good enough irrigation)?
As a rule of thumb, it’s best to assume that all studies like this are in mice or rats unless the headline specifically says “in human trials”.
Murine studies are a dime a dozen and therefore it’s the default assumption when reading research papers. When human trials commence the fact that it’s in humans is a big part of the research and therefore paper titles.
I would be in favor of adding a standardized [in mice] to the titles of all HN submissions about medical breakthroughs. Most of them end up being in mice and many do not reproduce in humans. It would help, at a glance, to know how significant a study's results are.
This works in mice with small tumors for two weeks until the experiment ends. It's quite different form working in humans with big tumors for 5 years.
Mice are good for early tries. The researchers had 9 bacterias and only 1 was successful. Experiments in mice are cheaper and have less ethical problems than experiments in humans.
(Hey! They even injected the cancer cells in mice and waited a week until it grow. Nobody will approve that in humans.)
I know hearing this gets old, however, please review sources outside of LLMs for accuracy. LLMs take a whole bunch off stuff from all over the internet and distill it down to something you can consume. Those sources include everything from reddit to a certain de-wormer that folks still think treats COVID (side note: I've a few long COVID victims in a support group I am in, and they are not happy about the disinfo that was spread, at any rate)...LLMs/"AI" does not and cannot innovate, it can only take all existing information it knows, mash it all together, and present you with a result according to what the model is trained on.
I'm not against AI summaries being on HN, however, users should verify and cite sources so others can verify.
However, I'm just a normal nerd that wants to fact check stuff. Perhaps I'm wrong in wanting to do this. We'll see.
I have significant experience in polymer chemistry, as an experiment, I decided to ask gemini some very specific questions to try and back it into a corner, so to speak. It blew me away with the answer, discussing quite a bit of info I was not even aware of.
> I'm not against AI summaries being on HN, however, users should verify and cite sources so others can verify.
I don't see how they contribute anything to a discussion. Even a speculative comment organically produced is more worthwhile than feeding a slop machine back into itself. I don't go out for coffee to discuss LLM summaries with friends, and I can't imagine why anyone would want to do that here.
Earlier today I asked Gemini Pro to find information on a person's death that was turning up nothing for me otherwise, and it just imagined finding verbatim Obituary quotes in every source, cobbled together vaguely related names, plausible bits and pieces from wherever, almost like it was 2023 again.
It ain't search, and it ain't worthwhile; I'd much rather someone ask an llm the question and then post a question out of curiosity based on it, but without the summary itself
> It is search if you ask it to produce a list of links.
Not in the example I mentioned. It can imagine the links, and the content of the links, and be very confident about it. It literally invented an obituary that didn't exist, gave me a link to a funeral home that 404'd, came up with "in-memoriam" references from regional newsletters that never contained her name. It's actually really scary how specifically fake it was.
I asked it to produce verbatim references from any sources and the links to them, and none of the text it produced could be searched with quotes on any search engine.
I think that's the tricky thing. I'm not saying it's not useful when it is, but you really do need a keen and skeptical eye to be able to know. The problem kind of reminds of bloom filters, such that they're useful for situations when you want to know something might exist or definitely does not exist in a set. Exact truth has some level of permissible error rate, as it does in any situation, but definitely wrong is pretty important to know about.
The issue as I see it is just straight copy/pasting its output. You want to use it as a search tool to give you pointers on things to look up and links to read? Great. Then use that as a basis to read the sources and write your own response. If you aren't familiar enough with the subject area to do that, then you also shouldn't be pasting LLM output on it.
It's not even copy/pasting in some cases. In my example, it confidentially produced "verbatim" references that don't exist anywhere, to specific pages that never mentioned this person's name or contained any of the text. Sometimes completely different people, 404 pages, huge waste of time
Yeah I agree, I've seen the hallucinated references also. Sometimes used by people in internet arguments to make their bullshit seem more legitimate. What I meant though by copy/pasting is people getting the LLM output and then just directly feeding that to the people they're conversing with, instead of looking into what it's saying or really even engaging with it in any way.
Ask it to solve a tough Euler Math puzzle with the search button on and it just copies the answer from the web. Turn search off and it actually computes the answer.
Funny how the search button is taken away though.
Which is "fine" so to speak. We do this with using AIs for coding all the time, don't we? As in, we ask it to do things or tell us things about our code base (which we might be new to as well) but essentially use it as a "search engine+" so to speak. Hopefully it's faster and can provide some sort of understanding faster than we could with searching ourselves and building a mental model while doing it.
But we still need to ask it for and then follow file and line number references (aka "links") and verify it's true and it got the references right and build enough of a mental model ourselves. With code (at least for our code base) it usually does get that right (the references) and I can verify. I might be biased because I both know our code base very well already (but not everything in detail) and I'm a very suspicious person, questioning everything. With humans it sometimes "drives them crazy" but the LLM doesn't mind when I call its BS over and over. I'm always "right" :P
The problem is when you just trust anything it says. I think we need to treat it like a super junior that's trained to very convincingly BS you if it's out of its depth. But it's still great to have said junior do your bidding while you do other things and faster than an actual junior and this junior is available 24/7 (barring any outages ;)).
I've had quite good luck asking Gemini and ChatGPT to include links to research papers for every claim they make. Not only can I review at least the abstracts but I find when I do this, they'll retract some of the hallucinations they've have made in prior messages. It almost seems (and maybe they do) in their web searching tools, reread the content they include. Thus, greatly reducing errors, with minimal extra effort on my part.
> Could it be that this organism switches to anaerobic respiration when it finds itself inside cancer tissue
Unlikely. The leading hypothesis is that mitochondria are a part of the apoptosis cycle, so cells need to disable them to become cancerous. This is called the Warburg effect.
There are several drugs that target this mechanism, inhibiting the anaerobic metabolism. They are effective initially, but cancers always find ways to work around them.
Now I can't wait for the conspiracy theory types to say this proves reptilian people theories. Lizard people just giving to help us accept them type of stuff, and maybe prove how the ape descendants need the lizard people.
I believe parent-poster is making a joke at the expense of conspiracy-theorists who believe in lizard-people, rather than endorsing the idea. To paraphrase, something like:
"This news article links human survival to something taken from amphibians and reptiles. There are conspiracy-theorists who posit the existence of Lizard people. It would be amusing if those humans discovered this news, and claimed it was a plot by Lizard People to make us dependent on them."
So there, I think I explained the joke... which isn't necessarily a good thing. In the words of E.B. White:
> Explaining a joke is like dissecting a frog. You understand it better but the frog dies in the process.
Now, I could work that new amphibian-connection into another joke... But let's face it, it would be "too meta" at this point.
I feel like sometimes the actual act of explaining the joke can actually be funnier than the joke itself. Occasionally when I can explain a super dirty joke with a deadpan and matter-of-fact tone people will laugh more than they would have if they had actually gotten the joke in the first place.
I have been working with my dad on his cancer treatment since last year. My interest in the topic has only peaked ever since.
(Disclaimer- I am an engineer and not a microbiologist/doctor)
Mutations and wrong copying of genome happens all the time in the body and some enzyme has the job of correcting the mutated genes so it doesn’t get into the system. Level 2 defence is T cells killing it as identified as foreign body.
Thing that baffles me is that I see most work happening to eliminate tumor. To me it sounds a tough problem given the permutation and combination of mutation— roughly few trillions.
But I was curious if there is working happening on L1 defence — fixing the enzyme that fixes the wrong copy paste mechanism. Or making the enzyme get more efficient and powerful. Is that line of thought even valid?
Our L1 defense is actually incredibly good. A human will undergo about 10^16 cell divisions over the course of their lifetime. Around 10^3 to 10^6 of those divisions will result in a mutation that gets past the L1 defenses and need to be eliminated by the T cells. It's not generally easy to make dramatic improvements to something with a 99.9999999% success rate.
The immune system is pretty good too, which means any given improvement to the replication system is, all else being equal, probably going to prevent mutations the T cells would already handle. If you need to do the research to figure out what's getting past the immune system anyways, and improving the immune system is lower hanging fruit, it's the logical place to start.
Thanks for these insights! Do you have any material or sources for a layman to learn more about this and where these numbers come from?
Aren't the elephants and whales orders of magnitude better than us at that though (they have roughly as many cancer as we do, but with respectively x100 and x1000 times as many cells.
Or is it the second layer that works better for them?
Different species do have different levels of protection, and different lineages tend to employ different methods of protection. For example elephants have numerous duplicates of cancer suppression genes, whereas naked mole rats produce a variant of hyaluronan which prevents tumor formation. When compared to other great apes, Humans seem to be worse at both layers of defense.
It's worth noting though that humans also have much higher levels of exposure to many carcinogens than most animals, and we screen for cancers at a much greater rate for humans, so just because a species has lower cancer rates doesn't necessarily mean their cancer defenses are better.
also, Elephants have a much higher copy number of a gene called p53/ It codes a protein that acts to force suicide in cells that have damaged DNA (think from UV light, cigarette smoke, age, etc). In cancer this is a common 'early' mutation that allows collection of further mutation and progession towards cancer. In having many more copies of p53, it makes it less likely the p53 function will be eliminated
I am not sure how much consensus there is around it but this is so cool I have to repeat it sorry: Whales and elephants do develop cancers but since those cancers also have mutations, well their cancers have cancers and overall the cancers are never able to grow big enough to threaten the whole organism.
Too big to fail basically
The idea that tumors develop their own tumors, suppressing cancer is known as the Hypertumor Hypothesis and, while it works in computer models, there isn't actually any evidence backing it up.
The hypothesis doesn't really resolve Peto's paradox, the observation that cancer rates don't scale directly with the number of cells in an organism. Not only do large organisms like whales get fewer cancers per cell division, small animals like mice get more cancers per cell division, which can not really be explained by a threshold beyond which hypertumors suppress tumors. The actual evidence suggests organisms just evolve whatever level of cancer resistance they need to have low odds of dying of cancer before something else kills them.
That being said, the main observation underpinning Peto's paradox was actually just due to lack of good data. Over the years much more data has been collected from animal autopsies and it turns out that big animals do get cancer and cancer rates actually do scale with body size, just different species have varying levels of cancer protection, with the levels of protection being similar in closely related species of different sizes.
This is a fascinating niche of evolutionary biology that I have worked in for a while. The short answer is that yes, as far as we can tell all organisms evolve increasingly more efficient replication machinery, however at some point the strength of selection is no longer powerful enough to overcome the strength of genetic drift and some degree of error rate persists. As far as we can tell it seems like population size governs where this balance ends up such that small populations have high mutation rates and large populations have reduced mutation rates. Michael Lynch coined the term drift barrier hypothesis to describe this phenomenon. https://pubmed.ncbi.nlm.nih.gov/23077252/
If the organism is too efficient at preventing mutations - it would evolve slower, right?
Yes, but note the mutation rate of germline cells - that are passed to your offspring and hence influence evolution - is estimated to be two orders of magnitude lower than other (somatic) cells.
Not necessarily if it had recombination (as in sexual reproduction), but as far as I understand, yes, you’d probably get fewer novel alleles/coding sequences of DNA generated per organism replication
It starts with mutations (sometimes accelerated by mutagens (smoke, alcohol, etc) or inflammation (viruses, infections, etc) or just chance (things like asbestos up the division rate by constant physical damage and thus up the probability or an error in copying).
But there is much more to it. This is a nice paper for an overview: Hallmarks of Cancer (tng) [0]. It (among others) adds the very important and for years underestimated role of the immune system to the original 2000 paper.
[0] https://www.cell.com/fulltext/S0092-8674(11)00127-9
Would sports also increase the rate of division? Bodybuilding for example you intentionally make micro tears in muscles to get them to repair and grow (lay person, apologies for the mistakes)
The problem is that many things that reduce the probability of cancer increase the probability of other diseases.
Therefore there is no good solution for this.
For instance, some studies have demonstrated that certain kinds of malnutrition, i.e. the consumption of inadequate amounts of protein and/or with bad amino-acid profile, inhibited the development of tumors caused by carcinogen agents (in rats and mice). This was not really surprising, because tumors grow faster than the rest of the body so they need to synthesize more proteins. If they are starved, they grow slowly and the immune system has time to react and to eliminate the incipient tumors early enough.
Despite this, starving yourself in the hope to avoid cancer would be a very bad idea. While the probability of cancer is lowered, the probabilities of low resistance to infectious diseases or of muscular weakness leading to falling and breaking some limb, or of cardio-vascular diseases, become higher.
Hmm, I'm a molecular biologist, not an expert at this particularly, what I do know is that damage of muscle fiber may not be necessarily mean new cell growth and thus extra DNA replication. The growth of the muscle cell certainly does.
Exercise is good for the immune system, this helps clear cancer, helps stay away from inflammation (ie auto-immune diseases). Where as a sedentary life style a poor diet will promote this.
But indeed for some things/behaviors, the relation the cancer may be complex.
L2 is being prioritized because our L1 defences are already very good. We are a long-lived species, and our natural ability to fix errors is so good that it is hard to improve upon. Maybe the long-lived tortoises or whales can do it better, maybe. But we have "several nines of reliability" there.
OTOH our L2 isn't that good, mammals in general (with some notable exceptions such as bats, whales and naked mole rats) are prone to cancer in their older age. There probably is a lot of relatively low-hanging fruit there.
If you think about it - individual cells aren't very precious and if some of them gets FUBARed by something (a virus, radiation or chemical insult), it is better to whack it and reuse the proteins to build a new one, if possible, instead of wasting time and resources on reconstruction of a total wreck.
Which also means that some research into replenishment of stem cells is necessary - and this is, IMHO, the really underfunded part of the whole thing. We lose a lot of stem cells as we age. Maybe we don't have to.
While cancer is caused by mutations in the genome, these mutations in turn produce the unifying property of cancer: unchecked cell replication.
Most cell types have systems to safely manage replication. Broadly, there are gas pedals (oncogenes) and brakes (tumor suppressors). A classic oncogene is something like RAS, which activates a signaling cascacde and stimulates progression through the cell cycle. A canonical tumor suppressor is something like TP53, the most frequently mutated gene in cancer, which senses various cellular stresses and induces apoptosis or senescence.
Most cancer genomes are more complicated than individual point mutations (SNPs), insertions, or deletions. There are copy number alterations, where you have > or < 2 copies of a genomic region or chromosome, large scale genomic rearrangements, metabolism changes, and extrachromosomal DNA. There is a series on the hallmarks of cancer which is a useful overview [1].
All of the mechanisms that intrinsically regulate cell growth would fall under your "L1 defense". Unfortunately, the idea of reversing somatic point mutations is likely to be a challenging approach to treating cancer given the current state of technology.
First, for the reasons above, cancer is often multifactorial and it would be difficult to identify a single driver that would effectively cure the disease if corrected. Second, we don't have currently delivery or in vivo base editing technology that is sensitive or specific enough to cure cancer by this means. There are gene therapies like zolgensma[2] which act to introduce a working episomal (not replacing the damaged version in the genome) copy of the gene responsible for SMA. There are also in vivo cell therapies like CAR T which attempt to introduce a transgene that encodes for an anti-cancer effector on T cells. These sorts of approaches may give some insight into the current state of art in this field.
Edit: also I should note that the genes involved in DNA repair (PARP, BRACA1/2, MSH2, MLH1, etc) are frequently mutated in cancers and therapeutically relevant. There are drugs that target them, sometimes rather successfully (e.g. PARP inhibitors). But the mechanisms of action for these therapies are more complicated than outright correcting the somatic mutations.
1. https://aacrjournals.org/cancerdiscovery/article/12/1/31/675... 2. https://en.wikipedia.org/wiki/Onasemnogene_abeparvovec
While I can't speak to whether there are enzymes for the proper copy/paste I do have a set of random cancer related bits I've picked up over the years.
There are some basic, well-known nutritional interventions that are generally important/critical for DNA repair processes. The 2 main ones are Vitamin D and Magnesium. Ensuring adequate amount of these tend to be helpful (most folks aren't getting enough sun and greens).
Other than that, a steady and adequate source of the substrates seems to be important: ie protein (nitrogen), and phosphates.
One of the interesting bits about some cancer cells is that while they simply haven't gone through apoptosis, physical sheer stress incurred from physical activity (exercise) can cause cancer cells that travel beyond the tumor point (before it becomes metastatic) to finally self destruct.
It seems important to me that the best strategy for cancer is the compounding of many different strategies that optimize the body's innate defenses to run optimally.
It does seem that ketogenic diets may have adjuvant properties, but there is yet to be a clinical trial that demonstrates it, so it's basically stuck in paper and R&D stages as to whether being in a ketogenic state can be one of the last areas that may help cancer patients extend lifetime from say 1 year to 2 years.
> To me it sounds a tough problem given the permutation and combination of mutation— roughly few trillions.
You are right. There is a very good explanation in this comic https://phdcomics.com/comics.php?f=1162
I know this is a bit off topic, but have you ever thought about why steroids and other forms of doping are not a free lunch? Why can't we just inject an external chemical to boost our strength for free without any side effects?
If steroids worked, everyone would be constantly injecting them. It would be like drinking coffee.
And that is the reason why steroid injections are harmful. If there is a free lunch, the human body will simply produce the optimal amount of steroids on its own until the Pareto frontier is reached and a tradeoff needs to be made.
Where does the body get the materials to form the steroids? From your diet. So the primary intervention is always a healthy diet and an active lifestyle. You know, the boring things that parents drill into their children.
It's valid but "medicine" that has only upsides and no downsides isn't medicine, it's diet.
I don't know the specifics of efforts to "repair" DNA replication repair (if you get my drift), but I suspect there is some effort in that area.
There definitely are efforts to correct enzymes involved in tumor-suppression (p53 is probably the best known tumor suppressor protein). e.g., here's a study on a small molecule designed to correct mutated p53 https://pmc.ncbi.nlm.nih.gov/articles/PMC8099409/
Cancer sucks and I wish your father the best.
Also not a doctor or microbiologist, but just wanted to share my layman’s guess on why fixing enzymes will not completely solve the issue: there’s 2 strands of DNA and to fix the broken (mutated) strand you need to have one correct template strand intact so you know what it should be fixed into. It could be the nucleotides swapped places between strands or are deleted completely or otherwise both mutated, which would mean any repair will not revert the sequence to what it used to be.
The other comments so far are probably more informed.
Cancer sucks, I wish all the best towards a recovery.
You’d also have to ‘fix’ DNA: unless we can re-engineer a bunch of key enzymes and then re-encode the entire genome (or maybe key parts) with forward error correction without breaking everything else, it might work. You might also break evolution to some degree by making random point mutations less likely.
But what I learned so far is that as soon as you’d attempt something like this in bacteria, the fitness advantage from an evolutionary standpoint is negligible compared to the efficiency loss introduced by FEC, so your colony would get outcompeted by other bacteria unless there is a niche your resistant bacteria survive in (high radiation environments?). The efficiency loss induced ‘disadvantages’ would probably be less pronounced in mammals though - If (big if) you manage to not also break anything essential in the wonderful yet surprisingly efficient Rube Goldberg machine that is life.
What I meant was there are collection of genes responsible for error correction. If there is a failure in duplication then these genes have not done their job.
Thought experiment, again as a layman, was to see if these genes responsible for error correction at the base level can be fixed or bolstered and that will act like a cancer vaccine. But looks like from other comments that this is even more harder!
> fixing the enzyme that fixes the wrong copy paste mechanism
The DNA fidelity issues contribute to only some cancers. Many are caused by mutations due to environmental damage and some are caused by viruses. The point is, there's a huge variety of reasons for developing cancer. So you cover more cases by developing treatments that are more "universal".
> fixing the enzyme that fixes the wrong copy paste mechanism. Or making the enzyme get more efficient and powerful
If we had the tools to easily do that we’d practically be gods.
> But I was curious if there is working happening on L1 defence — fixing the enzyme that fixes the wrong copy paste mechanism. Or making the enzyme get more efficient and powerful. Is that line of thought even valid?
Mutations in general are not the defining quality of cancer. It's mutations in these very L1 safeguards. There are several such safeguards and a cell needs several mutations in those to become malignant. Eg. https://en.wikipedia.org/wiki/P53
Correcting genes only works in certain conditions (e.g. limited single strand breaks), in a narrow time frame during cell division, safeguards rather trigger cell suicide, or if that fails they mark the cell for destruction by immune cells. A cell can't fix DNA which made it through cell division once, because it got nothing to proof-read against.
After the safeguards are gone, everything goes and genetic diversity increases quickly within each tumor. This diversity is what's making cancer treatment hard. At some point there won't be a shared vulnerability in all malignant cells. The repair mechanisms are working in favor of the cancer now. For example, with radiation therapy you preferably want to induce DNA double strand breaks, because cancer cells can't repair those. Otherwise you need to increase the radical burden enough to overwhelm repair, but migrating radicals may damage distant cells, too.
I presume you could hypothetically inject mRNA of a working safeguard gene (eg. P53) into all cells (at some point cancer cells can't be selected exclusively, since they lost identifying marks and present as stem cells), so the functional enzyme or transcription factor is forced to be built inside. I am sure people are trying this right now. However, the inner workings of cells on a molecular level are insanely complex and our understanding is only scratching the surface. As with P53, you have a transcription factor, which means it's modifying gene expressions elsewhere. It's only a small part of a complex regulatory cascade. I doubt there is a safeguard target, which can easily be injected without considering the precise timing and environment within that safeguard cascade in the cell. Of course, the rest of the safeguard system needs to be present in the cell to begin with. Mind you, you don't want to cause cell suicide in healthy cells, so you want to restore the function of whole selective complex.
Then there is the question of delivery. Can you deliver eg. the mRNA to every cell without raising suspicion of the immune system? With the COVID vaccine, the enabling breakthrough was the delivery vehicle, not as much the mRNA part. Can you even reach the cancer cells at all? Cancer cells are frequently cloaked, shadowed or cut of by senescent, or necrotic cells, or acquired unique ways of metabolic adaptations. A bit similar to bacterial persistence, like M. tuberculosis, which can evade bodily and chemical defenses for decades.
The take-away: Life is complex beyond comprehension! Despite simplifications taught in schools and reductionist zeitgeist, we actually know very, very little about what's going on in genetics and molecular biology, most medical knowledge is empiric guessing instead of explanatory understanding.
100% response, zero side effects?
This sounds like world changing news. Can anyone with domain expertise explain the catch, if any?
The catch is that there are thousands of promising therapies in animal models/pre-human testing. A very very tiny fraction of them will ever make it to market for a variety of both good and not-good reasons.
What's the difference between a good and not-good reason to not go to market?
Prevalence of the disease - if it only impacts 1/100 million, going to be hard to ever find sufficient patient population to test and recoup your investment.
Existing quality of treatments - if there are already efficacious drugs on the market - how sure are you that this new therapy will be best in class? Only being as good as the status quo is not an ideal competitive position. Conversely, if there is an unmet need because a disease is so lethal/debilitating, regulatory agencies can give latitude in approvals.
Likelihood patient compliance - if it is the most effective drug in the world, but requires intravenous infusion six times a day - nobody is going to adhere to that. GLP drugs are effective, but there is a needle-phobia that is preventing patients getting on board with the idea. Which is why there is an arms race for the first company to develop an oral version.
Toxicity - all chemicals are poisonous. Yet some have a lower therapeutic window than others. If you drug does what it should, but if you take 2x as much and it gives you a heart arrhythmia that is going to be a tough approval for anything but the most deadly conditions.
Also the ethically in blind studies, can't just let some random patients die just to prove that your drug works.
Yes, you can. The problem with testing is that a candidate treatment may make things worse for patients, not that it may improve things.
If your treatment works, that’s an improvement of what you had before. Once you know that, you can treat all patients. For some, that will be too late, but without your tests, it would be too late for them, too.
If your treatment doesn’t do anything at all, it keeps things the same, but the patients in the test group likely will have had some inconveniences (having to visit a doctor, getting an injection, etc), so you shouldn’t do the test.
If your treatment makes things worse, you of course shouldn’t do the test.
Problem is that you typically only can only know in hindsight which of these applies.
So, you think carefully on whether a treatment could fall in category 3, and, if so, first do it on a group of patients who consent to be Guinea pigs and, often, are already terminally ill, as any negative outcomes will cause less harm to such patients.
Then, as soon as during the test your stats tell the drug does or doesn’t work, you stop the test and either treat all patients or stop treating the test subjects.
When there is already a known treatment, the control group gets the old known treatment and the other group get the new proposed treatment.
So the comparison is between old and new, to ensure the new treatment is better than the current standard one.
I guess I'm not being clear. Are these examples of "good" or "bad" reasons to not go to market? I assume "good"? If so, what would be an example of "bad"? Or vice versa if your meaning was opposite.
I responded below already but since writing that, I've come up with a few more great bad reasons not to bring a drug to market (sorry for the parseability of that one...)
Best bad reason: it would cannibalize an inferior drug currently in your portfolio that's still under patent protection.
I think this behavior is at the far "evil" end of the spectrum of behaviors that drug developers systematically engage in (which I believe is far more banal + less evil than what they're accused of), but it does happen and it's a really nasty
Where it gets especially nasty is when companies buy drugs in development or pre-development from other companies in order to squash (or at least delay) a potentially competitive asset before it reaches the market.
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Another great bad reason, but mostly applies to devices/procedures: the device/procedure is fantastic but for various structural reasons outside of the control of the device/procedure developer, there is insufficient incentive for healthcare providers to actually deploy said device/procedure.
A trivial example would be a pacemaker that requires fewer leads than the competitors and has fewer complications. Great for patients, but potentially totally uninteresting to the electrophysiologists who install it and would get paid less due to the less complex procedure.
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Best good reasons all fall under: making a therapy is unfathomably difficult and most efforts are destined to fail OR (separately) proving a therapy works is unfathomably expensive and most efforts can't produce a positive ROI after that process.
Ultimately most of these decisions come down to economics and not mustache twirling villains. The banality of evil.
Simplest "bad" reasons are the wealth of the patients. Malaria, river blindness, guinea worm, etc are terrible diseases that mostly impact poor people out of sight from Western eyes. Spending $X billion developing a drug for a population that can barely afford to feed themselves is not going to make a financial return on investment.
Well, it would for those countries, but yes, it's not sensible for a private business with no guaranteed source of funding. If they did develop it and no one paid the PR would be even worse.
Rybelsus exists already, so there's that
Good reasons:
* Most drug candidates just don't work
* Even among the drug candidates that do, figuring how to safely deliver them to their target is very hard (looks similar to "just doesn't work")
Bad reasons:
* It's too expensive to prove that a drug works
* It's too difficult to differentiate the patients for whom a drug works and the patients for whom it does not
* It is very hard to predict recruitment and to actually recruit patients for clinical trials
* There aren't enough people with the disorder who are also rich enough to afford treatment to justify development
> It's too expensive to prove that a drug works
I'm not sure that is necessary a bad reason. You need to factor in a lot of concerns to determine what "too expensive" means.
But if you are going to spend billions of dollars to develop a drug that only treats about 2 people a year it is likely too expensive even if it is 100% effective. That money would be better spent on treatments that have wider applicability.
Of course this is not simple to measure. Costs aren't known upfront and the research may end up proving invaluable to more widely applicable treatments.
So it is a judgment call and not necessarily a bad reason.
Agreed it isn't necessarily a bad reason. In some cases it's a good reason for failure (like the one you describe).
In other cases it's a bad reason for failure: it's also incredibly expensive to prove your drug works even if it does work for a lot of people.
That's bad! It'd be better if it were cheaper.
Actually counterintuitively, due to a weird drug approval and payor reimbursement policy arbitrage, pharma companies are highly incentivized to produce drugs for tiny populations.
One of my hobby horses is railing against this specific dynamic.
There is also the ole', drug works 20% of the time and kills the patient 80% of the time.
A lot of potential treatments are too easily available and can't be patented. If a big pharma company can't make massive profit from it, they won't bother bringing it to market. Consider that a not-good reason.
Other treatments may eventually prove to have too many serious negative side effects. That's a good reason to abandon them.
> A lot of potential treatments are too easily available and can't be patented.
This isn’t really an obstacle, at least not as much as it’s made out to be.
There are numerous examples of drugs being brought to market at high prices despite having been generic compounds. Even old drugs can be brought back at $1000/month or more at different doses or delivery mechanisms.
One example: Doxepin is an old antidepressant that is extremely cheap. It was recently re-certified for sleep at lower doses and reintroduced at low doses at a much higher price, despite being “off patent”.
This happens all the time. The drug companies aren’t actually abandoning usable treatments due to patent issues as much as journalists have claimed. If they couldn’t, for some reason, find a way to charge for it they could still use it as a basis for finding an improved relayed compound with more targeted effects, better pharmacokinetics, etc.
They’re not just dropping promising treatments anywhere if there’s a market for them.
About Doxepin. As many seniors do, I also suffer from extreme inability to stay asleep at night. I have trialed through all the known prescription and non prescription possibilities, only eszopiclone and baclofen seem to show some promise, however, eszopiclone is DEA listed, requires higher and higher doses, and if I take it more than say 2 weeks, it has rather serious side effects attempting to withdraw, addictive, serious anxiety, trying to wean oneself off it. Doxepin is prescribed as an antidepressant in large doses, one of the most potent H1 histamine antagonists known. The H1 system in our bodies promotes wakefulness. In very low doses, doxepin acts against the H1 to promote sleep. To avoid the upcharges of low dose doxepin, I am prescribed the high dose version, which I have to break the capsules to administer about 5 to 10 mg. placed in an empty gelatin capsule (it's bitter). It really works well, however you are fairly tired and useless the next day.
Have you tried Cognitive Behavioral Therapy?
I am a lifelong sufferer of insomnia (though mostly sleep onset) and tried all sorts of increasingly risky things. CBT cured me in ~2 months.
Why would a China or India care if it were a viable treatment? Unless a country wants to use their population as lab rats, it takes money and scientists to actually confirm a treatment is safe and effective.
Obviously you use the neighboring country’s population, or an ethnic minority, or prisoners, or orphans, or…
Wonder if some form of FOSS approach would work as an alternative development model for pharma?
These folks gave an interesting talk on producing pharmaceuticals at defcon a couple years ago.
IIRC it was more about production methods than developing new treatments.
https://fourthievesvinegar.org/
This made me think of the "Institute for one world health" . It came out as a non-profit pharmaceutical company in the mid 2000's. Victoria Hale was the founder-it got her a MacArthur fellowship. It is focuses(focused?) on global health and populations underserved by for-profit models. I think they successfully developed a treatment for leishmaniasis. it's an adorable model and should be pushed but as usual it seems like the philantropy money is limiting.
Kind of like open source software.
In the early 2010s I had a couple friends working at a biotech startup with a moonshot cancer cure. They had amazing results in animal testing, and had raised just enough funding to do a first human trial on a terminal patient.
That patient was hit and killed by a car two days after finishing their treatment.
Along with the CEO's stubborn refusal to give up any more equity in the company, they went under, and the world will never know if that treatment worked.
From what I saw, there are very few experimental therapies that claim 100% efficacy, no side effect, no patent on complex engineering process to produce the drug.
I agree with GP that it is very notable.
I mean if it works on humans, which is not a stretch, colorectal cancer is done. It's huge.
Yes there are few that claim 100% efficacy and no side effect at this stage, but there are far, far, far fewer who make it to human availability.
I wouldn't describe it working in humans as "a stretch" per se. I'm not identifying a specific reason it shouldn't work in humans. I'm just saying that's true of thousands and thousands of really great looking treatments (per year!) that, nonetheless, end up not working in humans, or not being convincing enough to even warrant putting them in humans once.
If it is the case that there are such treatments (easy to produce, 100% efficacy, no side effect) that cure fairly common deadly disease such as colorectal cancer in mice, and that never make it to human trial, there is something seriously broken about medical research...
No, the issue is that mice are very different from humans.
The only thing such a state of affairs clearly indicates is broken is using mice as proto-human test subjects.
Which of course, when you state it like that, is obviously suboptimal. But no one knows what to do about it.
Mice are good because they are super cheap.
It's useful as a very early test. They used a shotgun approach, they tested 9 bacterias and 1 of them was suspenseful. At least it was suspenseful for 2 weeks, until the study ended. It's very difficult to extrapolate that to the 5 year survival rate in humans.
Correct, this is how drug development works.
Right, yes, at least that study proved that some bacteria eat cancerous cells in at least one mammal.
If that particular bacteria doesn't work in humans it may still trigger a search for a bacteria that does.
Still being optimistic about this :)
Yep, it's not wasted effort. This is how science works! Lots of dead ends and then suddenly a breakthrough.
Certainly good news for mice.
I wonder if anyone has tried to engineer a mouse that lives forever by applying all these life enhancing mouse therapies at once.
Yes, Mathuselah Mouse Price
Very small sample size and only in mice. Most experimental treatments don't make it to the clinic, and this could be another in a long list of exciting early results that don't lead to anything. However... These results seem too good to be true, but the paper actually seems pretty good. There have been other attempts to use anaerobic bacteria to treat cancer (as solid tumors tend to be hypoxic environments), this is the first I've seen that interacts with PD-1/PD-L1 pathway. This is the most promising cancer treatment I've seen in quite a while. Maybe we can be cautiously optimistic!
It looks like they screened 45 strains of bacteria to find 9 that passed their safety tests, and then only one of those had a 100-percent response. The sample size is also small: 5/5 sounds a lot less impressive than 100%. I'd expect the true response rate to be substantially lower ("winner's curse").
The bar for an acceptable side effect profile in an FDA-approved drug would also be a lot higher than "five genetically near-identical mice did not show evidence of pathology in a single study."
I'm not saying this work is bad (skimming, it seems fine for what it is, though haven't read in detail), but it's quite preliminary if we're talking about developing a medical treatment that could eventually be deployed in humans. There's a reason it ended up in a mid-tier microbiome journal.
I hesitate to link directly to a single podcast dealer, but if you search for Dave Ricks, CEO of Eli Lilly's podcast with Stripe brothers, there's some alpha in there.
A few years ago we also had 100% effective medication with zero side effects. Now birth rates are down, mortality up, and young people misteriosly die from cancer and hearth attacks.
Interesting article, but in the full paper their key figure (Fig 2) shows their treatment group of n=3 mice completely responded to the bacterial treatment, but their methods say they treated n=5 mice? Could be an honest mistake but that’s a little concerning for data manipulation.
Also agree that using a PD-L1 mab feels like it’s for show especially considering the cancer model they’re using (Colon-26) was shown to be substantially less responsive to PD-L1 inhibitors…
Not the world’s best paper imo
Still the idea is beautiful. Since tumors are oxygen-deficient and suppress the immune response, anaerobic bacteria would proliferate there, and wreak havoc, while in the healthy parts of the organism they would be rapidly eliminated. Additionally, since the bacteria accumulate in the tumor, and the immune system has just responded to their invasion, T-cells will flock to the tumor, destroying what remains of it in due course.
As they say, "the fame of a mathematician is measured by the number of poor papers", because pioneering works are often awkward, treading completely unknown ground. Maybe the same applies to biology sometimes?
I'm untrained in this area but it sounds like similar ideas I heard of in the last decade where injected tumor with virus (polio?) that quickly kills the tumor but then is easily cured in the rest of the body since we have solutions to them. Is this a similar situation?
Figures 2 and 3 seem to be different experiments, with n=3 and n=5, respectively. Both showed 100% survival. Obviously very small sample sizes, but still promising.
Yes in figure 2 it's 3 mice, next figure 3 they also have 5 (panel e)
I was impressed by the clarity and terseness of this little article. Is it common practice in the case of scientific articles coming from Japan?
https://www.tandfonline.com/doi/full/10.1080/19490976.2025.2... Link to the research article. Are you referring to the news release?
I know we're not supposed to edit titles, but I'm glad the submitter added "in mice". It avoided me quite the disappointment!
Previously: https://news.ycombinator.com/item?id=46283089
This segment about the mechanism is simple and very profound. I wonder if any cancer researchers here could comment on its universality across various types of cancers:
"Tumor-Specific Accumulation Mechanism
E. americana selectively accumulates in tumor tissues with zero colonization in normal organs. This remarkable tumor specificity arises from multiple synergistic mechanisms:
Hypoxic Environment: The characteristic hypoxia of tumor tissues promotes anaerobic bacterial proliferation
Immunosuppressive Environment: CD47 protein expressed by cancer cells creates local immunosuppression, forming a permissive niche for bacterial survival
Abnormal Vascular Structure: Tumor vessels are leaky, facilitating bacterial extravasation
Metabolic Abnormalities: Tumor-specific metabolites support selective bacterial growth
Excellent Safety Profile
Comprehensive safety evaluation revealed that E. americana demonstrates:
Rapid blood clearance (half-life ~1.2 hours, completely undetectable at 24 hours)
Zero bacterial colonization in normal organs including liver, spleen, lung, kidney, and heart
Only transient mild inflammatory responses, normalizing within 72 hours
No chronic toxicity during 60-day extended observation"
I have never once seen a promising cancer treatment I've heard of on the news help people. You hear about the breakthrough treatments all the time, but when people get cancer, all you ever hear about is people getting chemotherapy and radiation. Same old scary shit.
Well, I guess Leukemia has been somewhat cured I heard, so that's pretty huge. When I was a kid it was a death sentence IIRC.
I'm not a doctor, but in some fairness, I think there has been a lot of progress in chemotherapy and radiation. "Increasing 5-year-survivability by 0.5%" doesn't make a fun sexy headline, but that's still an achievement that required a lot of hard work and enough of those happening still adds up.
I agree with your overall point though; it's a little annoying that every few weeks we hear about a new experiment that seems to indicate that we'll have a radically new and effective form of treatment for cancer only for it to never materialize.
"Cancer" is a term that covers a lot of diseases. So there is a lot of research going into a lot of different things, and hence lots of announcements.
"Chemotherapy" again is a loaded term covering a lot of different drugs, drug combinations, protocols and so on. So yeah, a lot of cancer treatment us "chemo" - but today's chemo is far removed from 2000 chemo.
5 year survivability has increased tremendously over the last decades. We're not talking 0.5% here, breast cancer for example has gone from 72% to 93%. Early detection of prostrate cancer has near 100% survivability.
But you're right, improving survivability doesn't make for sexy headlines. Yes there's a social media appetite for "breakthroughs", but the underlying "boring" stuff is doing well, and getting better all the time. It's just not "news".
My mom died of cancer and had to suffer through chemo. It was in the early 2000s, so I'm curious to know if you know anything about these new chemos and what makes them different.
My condolences for your loss. Discussing things in general terms,while having a lived experience must be painful.
There are different cancers, different stages different, different chemos, and of course different people.
Ultimately individual experiences of chemo run the whole gauntlet. At one end it can be little more than a bit of fatigue, at the other end a horrendous nightmare.
Yes, chemo has, as it's goal, a poison function. It sets out to poison you, hopefully killing the cancer first. It's never going to be the "fun" part of treatment.
I'm not a Dr, much less a medical historian. I would be ill equipped to quote specific drugs or dosages. Outcomes however are easily Googled, and those don't seem to be controversial.
I get that improved statistics don't make individual loss any easier.
There are a few factors at play here, I think
* Many breakthroughs from the first research stages never make it into medical application.
* Many breakthroughs are touted as some kind of "novel treatment", but when they get into the hands of the doctor, they talk about it as chemotherapy, because it kills cancer cells. So you might not even notice that you're getting something novel.
* Many breakthroughs take decades until they actually land in mainstream treatment.
* Many breakthroughs are specific to some kinds of cancer.
That said, in most developed countries, survival rates/times for cancer have been steadily improving for decades.
It's a bit like with solar cell and battery tech breakthroughs: you hear about them all the time, but it takes 20 to 30 years until they make it to production. But both have been improving steadily for an impressively long time.
Yes, you only hear about the initial breakthrough. The regular news doesn't report the trials unless things go spectacularly wrong. And you don't hear about the successes using the therapy on patients where traditional treatments didn't work. And you don't hear about the treatments successful enough that they replace the traditional treatments. But they are there, being used and saving lives. A family member's prostate cancer metastasized after 20 years of hormone therapy, they refused chemotherapy, and had their life saved by radioligand therapy, a treatment not available just months earlier. No side effects beyond a dry mouth, and now off the more debilitating hormone treatments.
https://en.wikipedia.org/wiki/Monoclonal_antibody_therapy
These are not your parents cancer treatments.
Keytruda (pembrolizumab) has been pretty monumental.
There's also AIDS that I heard have been practically cured. Since then I have became less pessimistic about drug progress
AIDS has been treatable for a few decades, with good progression getting it to developing world and some towards a cure. That said, some of this recent progress has been impeded due to differing beliefs of some current governmental regulatory and research leadership, and beliefs that infectious disease treatments and vaccines are not needed for most people that are 'healty'.
It is my wish and my blessing that this is true
So maybe I am too much a layperson here, but even without any direct therapetutic effects, it is pretty remarkable to have an easily scalable mechanism to get self-replicating agents into tumors, but nowhere else, is it not?
Yes it is amazing! Solid tumors tend to be poorly oxygenated, as they don't have a good network of blood vessels to supply them. The bacteria in these experiments can only live in low oxygen environments, so they will multiply in the tumor and die in any other part of the body they end up in. It's a clever idea, hopefully it will be successful.
Even lay-er person, but maybe the specificity is not that impressive in mice? Perhaps when you scale to more complex animals it is inevitable to see false positives (detrimental effects to healthy cells)?
Who knows how much knowledge we eradicated due to not bothering with climate change and just letting species go extinct. Thankfully these were still here for this discovery.
Sorry, as someone in this field, this is bullshit. It is in mice.
Several things trigger my bullshit meter. Quote:
"This dramatically surpasses the therapeutic efficacy of current standard treatments, including immune checkpoint inhibitors (anti-PD-L1 antibody) and liposomal doxorubicin (chemotherapy agents)"
PD-L1 monoclonal antibodies are only effective against cancers that are, you guessed it, PD-L1 positive. At high percentages, ranging from 1 to 50%. Are these authors even familiar with the state of the art when it comes to cancer medications? Mouse tumors do not equate to people tumors. Many tumor types are not PD-l1 positive.
Doxy is an ancient SOC chemo.
This is a nothing burger.
Give me phase II/III clinical trials, and then let me know what their PFS/OS was after 5 years. and what the medians were at 3- and 5-years. Also, ORR and CR and needed.
CAR-T is ahead of the game, and will be the ultimate winner here as it grows to scale.
In my dad’s case- he had gastric melonama. We surgically removed it and as consolidation We administered pd-L1 Immune checkpoint inhibitor. Melonama recurred again in 6 months time. This time in esophagus.
As an engineer I think all drugs tested and efficacies studied are on statistically not so significant data points. Given the permutations and combinations far exceed the clinical trials available and hence everything post clinical trial is also just an extended trial.
Wonder How to fix this? I am assuming heLa cells etc are also not the right test setup to have better test results.
Keytruda, pembrolizumab, (what he probably received) can only do so much. If it was in his GI tract it was also elsewhere in multiple places. The PD-L1 drugs at this point have more than 400k patients treated, with decent efficacy. I'm sorry for your loss. If his melanoma had metastasized to his GI tract it was too late for anything except palliative care.
This drug has been used in a huge number of patients for more than 11 years; the next gen of drugs is currently being used. I'm sorry for my curt style of writing, but - people like your father have helped pave the way for that next generation of drugs by constraining clinical trial designs.
Nivumolab was the drug administered in adjuvant setting. Maybe you are right that 400k patient with decent efficacy - however pegged chances are about 70-80% and not 100. So my point is can there be a better test bench to try and inch closer to a better efficacy?
For example - if hela cells can be used for trials — can there be the cultured tissue be used instead of mice as day 1?
Also curious — how did the scientist decide on using a specific cell/protein to be used for checking if this is producing results. Is it a hunch or science ?
Seems like a very interesting approach, even if it’s early stage.
> Many tumor types are not PD-l1 positive. > Doxy is an ancient SOC chemo. This is a nothing burger.
Meh the research didn’t say those were state of the art, but that they were “common” treatments. In other words a baseline for a presumably cheap and well studied animal surrogate.
> CAR-T is ahead of the game, and will be the ultimate winner here as it grows to scale.
Last I read up on it last year CAR-T treatments struggled with solid mass tumors.
Many cancers don’t have unique proteins for CAR-T to target (similar to the pd-l1 issue).
Then CAR-T struggles getting the modified T cells into the solid mass tumors en masse. Interestingly this approach actually makes use of the tumor environment rather than be hindered by it.
> Sorry, as someone in this field, this is bullshit. It is in mice.
Nice to hear an expert opinion. Let's hope your comment goes back to black. I have a lot of question!
> This is a nothing burger.
Is it enough for a bread-mayo-bread sandwich? Lettuce?
IIUC the bacteria makes the cancer disappear for two weeks, until they end the study and kill the mice. (IIUC this is timeline is usual for very early studies.) They tried other bacterias and one of them made the cancer disappear for a few days, so I'm worried about the long time efficiency of this method.
Is injecting the bacterias a second time as efficient as the first time, or the inmune system kills the bacteria before they hurt the cancer?
What happen in case of metastasis? Each one must be injected with the bacterias or they will jump and make all of them disappear?
Does the bacteria infect other organs and kill you? Is there a good antibiotic in case the bacteria cause problems?
They used cancers that were 200mm3 (i.e. like a sphere of 7mm = 1/4 inch). What happens in bigger cancers? Does bigger cancer have better irrigation and make it more difficult for the bacteria to survive? What happens to tiny hidden metastasis (that probably still have good enough irrigation)?
http://news.bbc.co.uk/1/hi/health/4155522.stm
In case people don't want to click on a random link, it is actually quite interesting:
Crocodile blood antibiotics hope
Scientists are catching crocodiles and sampling their blood in the hope of finding powerful new drugs to fight human infections.
Even horrific fighting wounds on the animal heal quickly
Just FYI, this study was done in mice.
As a rule of thumb, it’s best to assume that all studies like this are in mice or rats unless the headline specifically says “in human trials”.
Murine studies are a dime a dozen and therefore it’s the default assumption when reading research papers. When human trials commence the fact that it’s in humans is a big part of the research and therefore paper titles.
I would be in favor of adding a standardized [in mice] to the titles of all HN submissions about medical breakthroughs. Most of them end up being in mice and many do not reproduce in humans. It would help, at a glance, to know how significant a study's results are.
Or alternatively, some marker to indicate the presence of an “only in mice” comment
Maybe we find out why things work in mice and not us.
This works in mice with small tumors for two weeks until the experiment ends. It's quite different form working in humans with big tumors for 5 years.
Mice are good for early tries. The researchers had 9 bacterias and only 1 was successful. Experiments in mice are cheaper and have less ethical problems than experiments in humans.
(Hey! They even injected the cancer cells in mice and waited a week until it grow. Nobody will approve that in humans.)
Thanks, we've inmiced the title.
Of course it was done in mice, tests with animals are obviously mandatory before human trials.
They've given more lives to humanity than humanity itself (j/k)
Ah, I was wondering if it was one of those. And of course there's a relevant xkcd [0]
[0] https://xkcd.com/1217/
No, it is not relevant in the least. Murine studies are a standard practice on the path to human trials.
Your link is not even about animal studies. It is about a petri dish.
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I know hearing this gets old, however, please review sources outside of LLMs for accuracy. LLMs take a whole bunch off stuff from all over the internet and distill it down to something you can consume. Those sources include everything from reddit to a certain de-wormer that folks still think treats COVID (side note: I've a few long COVID victims in a support group I am in, and they are not happy about the disinfo that was spread, at any rate)...LLMs/"AI" does not and cannot innovate, it can only take all existing information it knows, mash it all together, and present you with a result according to what the model is trained on.
I'm not against AI summaries being on HN, however, users should verify and cite sources so others can verify.
However, I'm just a normal nerd that wants to fact check stuff. Perhaps I'm wrong in wanting to do this. We'll see.
I have significant experience in polymer chemistry, as an experiment, I decided to ask gemini some very specific questions to try and back it into a corner, so to speak. It blew me away with the answer, discussing quite a bit of info I was not even aware of.
Cool story, bro.
> I'm not against AI summaries being on HN, however, users should verify and cite sources so others can verify.
I don't see how they contribute anything to a discussion. Even a speculative comment organically produced is more worthwhile than feeding a slop machine back into itself. I don't go out for coffee to discuss LLM summaries with friends, and I can't imagine why anyone would want to do that here.
Earlier today I asked Gemini Pro to find information on a person's death that was turning up nothing for me otherwise, and it just imagined finding verbatim Obituary quotes in every source, cobbled together vaguely related names, plausible bits and pieces from wherever, almost like it was 2023 again.
It ain't search, and it ain't worthwhile; I'd much rather someone ask an llm the question and then post a question out of curiosity based on it, but without the summary itself
It is search if you ask it to produce a list of links.
It does well at filtering information for you.
Going to primary sources is required to verify what it says but it can reduce the leg work rather a lot.
> It is search if you ask it to produce a list of links.
Not in the example I mentioned. It can imagine the links, and the content of the links, and be very confident about it. It literally invented an obituary that didn't exist, gave me a link to a funeral home that 404'd, came up with "in-memoriam" references from regional newsletters that never contained her name. It's actually really scary how specifically fake it was.
I asked it to produce verbatim references from any sources and the links to them, and none of the text it produced could be searched with quotes on any search engine.
Yeah it does punt sometimes but often it works well. Especially on more well written about topics.
I think that's the tricky thing. I'm not saying it's not useful when it is, but you really do need a keen and skeptical eye to be able to know. The problem kind of reminds of bloom filters, such that they're useful for situations when you want to know something might exist or definitely does not exist in a set. Exact truth has some level of permissible error rate, as it does in any situation, but definitely wrong is pretty important to know about.
The issue as I see it is just straight copy/pasting its output. You want to use it as a search tool to give you pointers on things to look up and links to read? Great. Then use that as a basis to read the sources and write your own response. If you aren't familiar enough with the subject area to do that, then you also shouldn't be pasting LLM output on it.
It's not even copy/pasting in some cases. In my example, it confidentially produced "verbatim" references that don't exist anywhere, to specific pages that never mentioned this person's name or contained any of the text. Sometimes completely different people, 404 pages, huge waste of time
Yeah I agree, I've seen the hallucinated references also. Sometimes used by people in internet arguments to make their bullshit seem more legitimate. What I meant though by copy/pasting is people getting the LLM output and then just directly feeding that to the people they're conversing with, instead of looking into what it's saying or really even engaging with it in any way.
Ask it to solve a tough Euler Math puzzle with the search button on and it just copies the answer from the web. Turn search off and it actually computes the answer. Funny how the search button is taken away though.
> It is search if you ask it to produce a list of links.
Unfortunately it can hallucinate those too. I've had ChatGPT cite countless nonexistent academic papers, complete with links that go nowhere.
Which is "fine" so to speak. We do this with using AIs for coding all the time, don't we? As in, we ask it to do things or tell us things about our code base (which we might be new to as well) but essentially use it as a "search engine+" so to speak. Hopefully it's faster and can provide some sort of understanding faster than we could with searching ourselves and building a mental model while doing it.
But we still need to ask it for and then follow file and line number references (aka "links") and verify it's true and it got the references right and build enough of a mental model ourselves. With code (at least for our code base) it usually does get that right (the references) and I can verify. I might be biased because I both know our code base very well already (but not everything in detail) and I'm a very suspicious person, questioning everything. With humans it sometimes "drives them crazy" but the LLM doesn't mind when I call its BS over and over. I'm always "right" :P
The problem is when you just trust anything it says. I think we need to treat it like a super junior that's trained to very convincingly BS you if it's out of its depth. But it's still great to have said junior do your bidding while you do other things and faster than an actual junior and this junior is available 24/7 (barring any outages ;)).
I've had quite good luck asking Gemini and ChatGPT to include links to research papers for every claim they make. Not only can I review at least the abstracts but I find when I do this, they'll retract some of the hallucinations they've have made in prior messages. It almost seems (and maybe they do) in their web searching tools, reread the content they include. Thus, greatly reducing errors, with minimal extra effort on my part.
> Could it be that this organism switches to anaerobic respiration when it finds itself inside cancer tissue
Unlikely. The leading hypothesis is that mitochondria are a part of the apoptosis cycle, so cells need to disable them to become cancerous. This is called the Warburg effect.
There are several drugs that target this mechanism, inhibiting the anaerobic metabolism. They are effective initially, but cancers always find ways to work around them.
I'm happy to wait for the experimentation to weigh in for this one dawg
"according to Gemini" ........
aCcoRdinG To gEmiNi
Now I can't wait for the conspiracy theory types to say this proves reptilian people theories. Lizard people just giving to help us accept them type of stuff, and maybe prove how the ape descendants need the lizard people.
Need the what now?
I believe parent-poster is making a joke at the expense of conspiracy-theorists who believe in lizard-people, rather than endorsing the idea. To paraphrase, something like:
"This news article links human survival to something taken from amphibians and reptiles. There are conspiracy-theorists who posit the existence of Lizard people. It would be amusing if those humans discovered this news, and claimed it was a plot by Lizard People to make us dependent on them."
So there, I think I explained the joke... which isn't necessarily a good thing. In the words of E.B. White:
> Explaining a joke is like dissecting a frog. You understand it better but the frog dies in the process.
Now, I could work that new amphibian-connection into another joke... But let's face it, it would be "too meta" at this point.
I feel like sometimes the actual act of explaining the joke can actually be funnier than the joke itself. Occasionally when I can explain a super dirty joke with a deadpan and matter-of-fact tone people will laugh more than they would have if they had actually gotten the joke in the first place.
I'll agree that my attempt at humor was bested by someone else's explanation being much more comical