>To be clear, all of these conclusions can be true, and in some cases we know they are true, at least in part. For some cancers, treatments have improved, and for some, additional screening would save lives. But to support these conclusions, we need other methods and metrics – notably randomized controlled trials that compare mortality.
the economist put out a piece a few months ago providing just that. Specifically it compares overall cancer mortality rates (and more interestingly, mortality rates adjusted for age) and shows that cancer deaths have been dropping.
You don't not treat the control group. You give the control group the current standard treatment, and you give the experimental group the new trial treatment.
Randomized controlled trials are a bummer of a 'gold standard'. Extremely expensive, extremely slow and in many cases absolutely impossible. I'm not an AI true believer, but I do hope it offers an alternative or at least enables some desperately needed efficiencies.
But seriously: this is a recognized problem in medicine and there's already a widely used solution. Whenever you're doing trials of an intervention for a condition which already has an accepted treatment, you run a trial to compare your new intervention to that, and see if your test group has better outcomes. After all, the question shouldn't be whether your treatment is effective; it's whether it's better than existing treatments.
Trials against a placebo have a purpose, but they aren't the only way to run a trial.
RCTs aren't always necessary to change the medical standard of care. Sometimes lower quality studies plus a theoretical understanding of the physiologic is good enough.
There has never been an RCT to show that smoking causes lung cancer but doctors now all recommend that their patients not smoke.
I'm surprised this doesn't really talk about the thing that was most obvious to me: assuming the 5 year survival rate is five years from diagnosis, that means that if a tumor is diagnosed earlier, even if the cancer kills you, your death is more likely to be outside the five year window.
So for example, if you have (hypothetically) an untreatable cancer that would take six years to kill you, if it is diagnosed right away, you would be counted as a survivor, but if you are diagnosed at year five, you'll only survive a year.
Tumour evolution and progression is complex, being diagnosed early does not guarantee a linear growth. Even when it's biopsied at a timed interval you can't get a full picture of the cancer (invasive pattern etc) evolution trajectory. In some cases low grade tumours will be put on surveilance without radical treatment.
Diagnosis is complex too, you don't want the test to have low specificity. False positive is sometimes tolerated.
Colon cancer is an interesting one, Hank Green [1] recently covered a new paper [2] that showed a massive reduction in colon cancer risk for folks that engaged in moderate, regular, exercise. The authors speculated that mechanical stress leading to increased shedding might play an important role.
Weirdly enough that's the same mechanism hypothesized to play a partial role in why breast feeding is also associated with a reduced cancer risk.
imho if you don't exercise regularly and don't eat clean you're asking for troubles and simply can't complain about your health. The vast majority of people seem not to care until they get a serious diagnostic, by that time you can barely mitigate the issue. It certainly isn't a silver bullet, but at least it stacks the odds in your favor.
But that's haaard. Can't I just do the easy solution instead? Don't you have a pill I can take or something?
Aldous Huxley was correct, we truely are amusing ourselves to death. The new meta glasses are really scaring me.
Sorry for the doomerism. There's lots of other stuff to be optimistic about. Maybe this is just an evolutionary filter. Those that fit into these new circumstances will survive.
There are a lot of weird health statistic anomalies around the world. For example, the 11% of US adults are smokers compared to 17% in Japan and 25% in Spain. But both Japan and Spain have a lower lung-cancer incidence rate than Americans (Spain is much lower than both!)
Is the rate of cancer actually low or are a lot of cases never formally diagnosed? People in India might not "exercise" much in terms of going to the gym or running but they might still be physically active in other ways.
>The purpose of the model is to show that we can reproduce the survival rates we see in reality, even if there are no effective treatments.
That's a great argument in the abstract, but it ignores the fact that there are effective treatments for colon cancer. The fact that we can reproduce real survival rates in a counterfactual world where there are no effective treatments for colon cancer does not actually give us a model of the real world because the counterfactual explicitly contradicts known scientific facts.
What you have to do in order to make this argument is to show that there are Markov models where early detection does not work despite the fact that some cancers will cause death if untreated and not if treated. You cannot simply rely on models that have clearly impossible transition probabilities. You need possible models. Or you have to show that the absolutely massive amount of scientific literature and clinical experience about how to treat colon cancer is somehow flawed.
Some people are defending this because the blog post is attacking a specific argument, but I don't see how that can work. I am pretty sure that Nassim Taleb and most other people who are capable of putting together a coherent statistical argument (even a flawed one) understand that colon cancer can be treated sometimes.
I think this is a technical article about a narrow aspect of public health policy, not advice to individual patients.
One point in the article is that early detection would give you more years to live even if there were no treatment. Because "early" means "more years". This wasn't obvious to me right away.
But he is not saying don't get screened! He is not saying there are no cancer treatments! He's saying that the 5-year survival rate, considered alone, is a tricky measure that can fool our intuition. In my case he's right.
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Details.
Dumb toy model. Let Tumor X kill you exactly 8 years after it becomes detectable in screening. Assume screening is 100% accurate with no false positives. Assume X cancer kills you exactly 2 years after it causes symptoms. Imagine that there is no treatment for X cancer.
In this dumb model, everybody dies at exactly the same time after the tumor became detectable. The people who caught it in screening had more warning, but otherwise they didn't get a better outcome. Even though screening boosts the 5-year survival rate from 0% to 100%.
Never mind his like 7-state Markov model. OMG. Why.
Of course they're misleading.
What did the doctor tell us when my mom was diagnosed? Don't do research, do not trust Dr. Google, Dr. Google lies. At best, Dr. Google is behind the times.
The specifics of your case will strongly affect what happens to you.
And even for cancers that are a guaranteed death sentence, survival has increased significantly in recent years.
Go ahead, tell them the aggressive mass in their brain, the thing that shortened whatever potential life expectancy they had to, at best, single digit years, isn’t a guaranteed death sentence.
They’ll be so comforted by the idea that maybe their already shortened life expectancy will be further reduced by a car accident or some idiot with a knife.
This article is a criticism of reasoning, not health advice or suggestions for cancer screening. Maybe he should put a big warning at the top, rather than explain it throughout. A lot of people seem to be missing it.
We're so used to argument that criticizing logic is taken as criticizing the conclusion.
The only thing the author seems to be directly arguing against is speculative full-body MRI scanning, which is already mainstream medical advice, for many of the reasons he offers.
> We're so used to argument that criticizing logic is taken as criticizing the conclusion.
This may be so, but his examples are so poor that one is distracted from any type of subtle claim he would make. They are bad in obvious ways (every cancer patient is staged, but we pretend in the article like staging is ancillary to researching survival rates).
This article, in the world as it exists right now, is wrong about colon cancer. Anyone reading this of a certain age: get that colonoscopy, and those polyps removed. Snip it in the bud. That's the great thing about a colonoscopies - all-in-one screening + treatment.
Large prospective cohorts (Nurses’ Health Study + Health Professionals Follow-Up Study) with long follow-up - screening colonoscopy was associated with a 68% lower risk of death from colorectal cancer overall (multivariable HR ≈ 0.32, 95% CI 0.24–0.45) and showed significant reduction for proximal colon mortality as well (HR ≈ 0.47, 95% CI 0.29–0.76).
> For colon cancer, the rates from the SEER data are are 91%, 74%, and 16%.
This is the only claim the article makes directly about colon cancer. Otherwise, it's saying that early detection being beneficial isn't supported by survival rates alone.
Readit News
the economist put out a piece a few months ago providing just that. Specifically it compares overall cancer mortality rates (and more interestingly, mortality rates adjusted for age) and shows that cancer deaths have been dropping.
https://www.economist.com/briefing/2025/07/17/the-world-is-m...
https://archive.is/TNjoi
Putting people into a control group so you can observe the effects of not treating them might not make it past the ethics committee.
In the current trials a part of the subjects get the new experimental drug and the control group get the current state of the art treatment.
https://www.bmj.com/content/363/bmj.k5094
But seriously: this is a recognized problem in medicine and there's already a widely used solution. Whenever you're doing trials of an intervention for a condition which already has an accepted treatment, you run a trial to compare your new intervention to that, and see if your test group has better outcomes. After all, the question shouldn't be whether your treatment is effective; it's whether it's better than existing treatments.
Trials against a placebo have a purpose, but they aren't the only way to run a trial.
There has never been an RCT to show that smoking causes lung cancer but doctors now all recommend that their patients not smoke.
So for example, if you have (hypothetically) an untreatable cancer that would take six years to kill you, if it is diagnosed right away, you would be counted as a survivor, but if you are diagnosed at year five, you'll only survive a year.
Diagnosis is complex too, you don't want the test to have low specificity. False positive is sometimes tolerated.
Weirdly enough that's the same mechanism hypothesized to play a partial role in why breast feeding is also associated with a reduced cancer risk.
Fascinating, weird, stuff.
1. https://www.youtube.com/watch?v=4RXSX93mvg8
2. https://www.nejm.org/doi/pdf/10.1056/NEJMoa2502760
Aldous Huxley was correct, we truely are amusing ourselves to death. The new meta glasses are really scaring me.
Sorry for the doomerism. There's lots of other stuff to be optimistic about. Maybe this is just an evolutionary filter. Those that fit into these new circumstances will survive.
That's a great argument in the abstract, but it ignores the fact that there are effective treatments for colon cancer. The fact that we can reproduce real survival rates in a counterfactual world where there are no effective treatments for colon cancer does not actually give us a model of the real world because the counterfactual explicitly contradicts known scientific facts.
What you have to do in order to make this argument is to show that there are Markov models where early detection does not work despite the fact that some cancers will cause death if untreated and not if treated. You cannot simply rely on models that have clearly impossible transition probabilities. You need possible models. Or you have to show that the absolutely massive amount of scientific literature and clinical experience about how to treat colon cancer is somehow flawed.
Some people are defending this because the blog post is attacking a specific argument, but I don't see how that can work. I am pretty sure that Nassim Taleb and most other people who are capable of putting together a coherent statistical argument (even a flawed one) understand that colon cancer can be treated sometimes.
One point in the article is that early detection would give you more years to live even if there were no treatment. Because "early" means "more years". This wasn't obvious to me right away.
But he is not saying don't get screened! He is not saying there are no cancer treatments! He's saying that the 5-year survival rate, considered alone, is a tricky measure that can fool our intuition. In my case he's right.
---------------------
Details.
Dumb toy model. Let Tumor X kill you exactly 8 years after it becomes detectable in screening. Assume screening is 100% accurate with no false positives. Assume X cancer kills you exactly 2 years after it causes symptoms. Imagine that there is no treatment for X cancer.
In this dumb model, everybody dies at exactly the same time after the tumor became detectable. The people who caught it in screening had more warning, but otherwise they didn't get a better outcome. Even though screening boosts the 5-year survival rate from 0% to 100%.
Never mind his like 7-state Markov model. OMG. Why.
The specifics of your case will strongly affect what happens to you. And even for cancers that are a guaranteed death sentence, survival has increased significantly in recent years.
Go ahead, tell them the aggressive mass in their brain, the thing that shortened whatever potential life expectancy they had to, at best, single digit years, isn’t a guaranteed death sentence.
They’ll be so comforted by the idea that maybe their already shortened life expectancy will be further reduced by a car accident or some idiot with a knife.
We're so used to argument that criticizing logic is taken as criticizing the conclusion.
This may be so, but his examples are so poor that one is distracted from any type of subtle claim he would make. They are bad in obvious ways (every cancer patient is staged, but we pretend in the article like staging is ancillary to researching survival rates).
Evidence: https://www.nejm.org/doi/full/10.1056/NEJMoa1301969
Large prospective cohorts (Nurses’ Health Study + Health Professionals Follow-Up Study) with long follow-up - screening colonoscopy was associated with a 68% lower risk of death from colorectal cancer overall (multivariable HR ≈ 0.32, 95% CI 0.24–0.45) and showed significant reduction for proximal colon mortality as well (HR ≈ 0.47, 95% CI 0.29–0.76).
This is the only claim the article makes directly about colon cancer. Otherwise, it's saying that early detection being beneficial isn't supported by survival rates alone.
That claim may be obvious to everybody except me. Anyway it turns out to be true.