Very good post. And when you factor in Lead time Bias and Length time bias, the screening of the well population makes no sense at all. But humans make decisions based on emotion, not reason or data, something I have learned trying to teach EBM to students over the years. In covid, our politicians and health bureaucrats spent Billions doing PCR tests on well patients for god's sake ! This alone convinced me that humans are just irrational and you are probably wasting your breath ( or typing hand , lol. )
With cologard style tests, why not just use them? If something hideous is found, then decide on next steps. Why subject everyone to a test that generally isn't adding to longevity in majority of people?Additionally, The public generally doesn't want to address stats on those topics. And even worse big pharma hides real data, skews it, then people get even more confused. A .05% difference between tested v. nontested isn't enough to make me risk a puncture from a colonoscopy, esp if I have zero family history of the disease. Not to mention the horrible consequenses from being sedated repeatedly. No one even mentioned your long term risks from sedations....
We are stuck in the early detection mentality of the 1970s and 80s, which was predicated on a belief that we could catch disease early in every patient and that cancer was a single disease. Now that we know better, we need personalized screening. Personalized means complicated which means one size does not fit all and that will be difficult. The other part about screening is that no one is in charge. It’s the same with cancer prevention. No primary care physician or even breast surgeon/gastroenterologist is paid for counseling and prevention of disease. It will require a reboot of the system to prioritize this prevention and early detection model.
You are correct that the perceived benefit of CRC screening is orders larger than the actual benefit, and we should modify public policy accordingly. But competing risks do not logically defeat screening, and one bad test may be insufficient evidence for stopping testing of asymptomatic people entirely. If the significant risk of death accumulates from additive, unrelated, statistically insignificant components, we ought to improve screening technologies such that they can reduce some of these component-risk-factors and ultimately reduce the significant death risk.
We shouldn't really conflate one test's merit with the entire screening enterprise. After all, today's paradigms are not tomorrow's, and it's not clear when these paradigms shift.
Isn’t the better conclusion that invasive, single-disease screening needs a very high evidentiary bar when the absolute cause-specific mortality risk is tiny?
The assessment is different when N=1 (you) vs N=100,000,000. “Sorry you’ve got colon cancer but most of the other people didn’t need screening” isn’t a very comforting support for withholding readily available testing. Same for PSA tests: I don’t really care about everybody else’s odds too much when it comes down to checking ME.
I had one parent die of it at 69. My old GE doctor said that made me high risk. He retired. My new GE doctor says no, to be considered high risk I need TWO family members to have died of it, even if they’ve died from all kinds of other cancer (breast, uterine, ovarian).
Is this rationing healthcare for old people or is it reasonable?
I see the point , but I don't want to die of something preventable because it costs money. I'm not willing to play the odds with health issues. As long as I can cover costs, I will practice preventive self care. BTW cash pay for colonoscopy is surprisingly inexpensive.
Keeping in mind also that most adenoma do not progress, and some regress. For example, at autopsy at least 30-40% of people have adenomas, and the adenoma detection rarte in 40 year olds is 30% or more, yet 30% of people do not get colon cancer, and that was true before colonoscopies.
The VA likely funded it based on the influence of a key UCSD-administrator (Vice-Chancellor for Health Sciences), probably as a bonus check for past service (is that about right, Dr Carethers).
The data highlight competing mortality risk, especially in older adults, but this should refine rather than dismiss screening. Evidence shows colorectal screening lowers cancer incidence and mortality, so decisions should be individualized based on age, comorbidity, and life expectancy rather than a single risk comparison.
A better heuristic is to ignore what tests are available in the marketplace and identify your own top tier health risks and address those through 1. Lifestyle 2. Medications (if needed) 3. Specific testing. With #1 separated by 10 miles from #2, which is a mile apart from #3.
I think this whole argument leans too heavily on the wrong endpoint.
Mortality doesn’t capture what colon cancer actually does to people.
In my world, colorectal cancer isn’t just about whether someone dies at 10 years. It’s everything that comes with it. I see patients whose cancers were found early on screening and they’re done with a polyp removal or a straightforward surgery. I also see the other side. Big operations, ostomies, chemo, neuropathy, years of follow up, and a life that looks very different even if they’re technically “alive” at the end of it.
Those two scenarios are treated the same if you’re only looking at mortality. That’s the problem.
The other piece is that colonoscopy isn’t just detecting cancer. It’s preventing it. When you remove an adenoma, you’re changing whether that patient ever has to go through any of this at all. That doesn’t show up well in a mortality ratio, especially over a 10 year window.
So when we start saying things like “you’re 96 times more likely to die of something else,” it sounds convincing, but it’s really answering a different question. It’s comparing causes of death at a population level. It’s not asking what happens to the individual patient if this cancer shows up and whether we could have prevented it.
How about an endpoint like “Can this help you avoid becoming a cancer patient in the first place, or at least make that experience a lot life altering if it happens?”
It isn't all about one actuarial metric of lifespan. Advanced colon cancer is a grim way to spend ones last years. And early-stage colon cancer very often be addressed successfully simply by snipping polyps. Or surgical intervention that, while more iinvasive, is still relatively minor compared to being fitted with a colostomy bag. Or the prospect of dying in agony without treatment.
By contrast, conditions like COPD and congestive heart failure, undeniably more common as a cause of death, aren't really amenable to any reversal of the condition by any intervention, surgical or otherwise. Lifespan can be extended with medications and oxygen tanks. These conditions are tragedies, but they take the form of a slowly creeping decline toward a final demise, compared to the intractable pain and disability found in many cases of inoperable malignant tumors.
Monetary expense also has to be mentioned: how many colonoscopies can be done for the cost of one major surgery and follow-up for a case of advanced bowel cancer? Or should "we" simply euthanize people over 75, if they're found with advanced colon cancer?
Even given the current standard cost range for colonoscopies*, how are they not a bargain, given that even a procedure that finds and removes precancerous or cancerous polyps isn't remotely as invasive, costly, and exhausting to monetary resources and physical reserves as major inpatient bowel surgery with a lengthy follow-up of a chemotherapy and/or radiation treatment regime?
[*$2,000-$4,000 baseline; the cost is typically much more when insurance is billed, which everyone accepts as taken for granted, although nonetheless mystifying.]
Voluntary euthanasia is the solution to advanced colon cancer. If you offered people a luxury overseas holiday in exchange for euthenasia (funded by all the money that's saved in end of life care) some of us would be thrilled.
"How does it make sense to look for one disease when you are 36-90 times more likely to die from something else. I am asking. Tell me."
Because it reduces my risk of dying by 1% to 2.7%.
Would you put a 91-chamber revolver to your head with a bullet in one chamber, spin the barrel, and pull the trigger? How about a 37-chamber revolver?
I bet no.
And what if we could ALSO screen for some or all of those other causes? Would you not do that, because any one of them only has a small chance of killing you?
I think the main takeaway point is that this would be a personal decision that rational people would decide very differently. We need to inject some more personalized and data-driven information so that patients are best able to make their own decisions. Some people will hear that they can decrease their risk of something that they have a 2-3% chance of developing over the next 10 years and they will jump at the opportunity - they'll get the colonoscopy. Other people will hear that they have that chance and will say they have no interest in spending time, effort, money on screening for something they have a 2% risk of. People have vastly differing values.
what our current system does is strong arm all people into getting screened. We don't give them hard data on their risk and by how much said screening might reduce it.
We've been given a box to check and we want to check it. Again, main point being this attitude (driven by quality metrics and other external forces) highly inflates how effective these tests are and inflates each person's actual risk of the condition.
That is not to say that nobody should be screened - but recognize and admit what the benefits generally would be.
Very good post. And when you factor in Lead time Bias and Length time bias, the screening of the well population makes no sense at all. But humans make decisions based on emotion, not reason or data, something I have learned trying to teach EBM to students over the years. In covid, our politicians and health bureaucrats spent Billions doing PCR tests on well patients for god's sake ! This alone convinced me that humans are just irrational and you are probably wasting your breath ( or typing hand , lol. )
Having said that, I do applaud your efforts!
With cologard style tests, why not just use them? If something hideous is found, then decide on next steps. Why subject everyone to a test that generally isn't adding to longevity in majority of people?Additionally, The public generally doesn't want to address stats on those topics. And even worse big pharma hides real data, skews it, then people get even more confused. A .05% difference between tested v. nontested isn't enough to make me risk a puncture from a colonoscopy, esp if I have zero family history of the disease. Not to mention the horrible consequenses from being sedated repeatedly. No one even mentioned your long term risks from sedations....
We are stuck in the early detection mentality of the 1970s and 80s, which was predicated on a belief that we could catch disease early in every patient and that cancer was a single disease. Now that we know better, we need personalized screening. Personalized means complicated which means one size does not fit all and that will be difficult. The other part about screening is that no one is in charge. It’s the same with cancer prevention. No primary care physician or even breast surgeon/gastroenterologist is paid for counseling and prevention of disease. It will require a reboot of the system to prioritize this prevention and early detection model.
You are correct that the perceived benefit of CRC screening is orders larger than the actual benefit, and we should modify public policy accordingly. But competing risks do not logically defeat screening, and one bad test may be insufficient evidence for stopping testing of asymptomatic people entirely. If the significant risk of death accumulates from additive, unrelated, statistically insignificant components, we ought to improve screening technologies such that they can reduce some of these component-risk-factors and ultimately reduce the significant death risk.
We shouldn't really conflate one test's merit with the entire screening enterprise. After all, today's paradigms are not tomorrow's, and it's not clear when these paradigms shift.
Isn’t the better conclusion that invasive, single-disease screening needs a very high evidentiary bar when the absolute cause-specific mortality risk is tiny?
The assessment is different when N=1 (you) vs N=100,000,000. “Sorry you’ve got colon cancer but most of the other people didn’t need screening” isn’t a very comforting support for withholding readily available testing. Same for PSA tests: I don’t really care about everybody else’s odds too much when it comes down to checking ME.
I had one parent die of it at 69. My old GE doctor said that made me high risk. He retired. My new GE doctor says no, to be considered high risk I need TWO family members to have died of it, even if they’ve died from all kinds of other cancer (breast, uterine, ovarian).
Is this rationing healthcare for old people or is it reasonable?
I see the point , but I don't want to die of something preventable because it costs money. I'm not willing to play the odds with health issues. As long as I can cover costs, I will practice preventive self care. BTW cash pay for colonoscopy is surprisingly inexpensive.
We look because we can.
If anything, screening simply shifts the causes of death from one chapter of the ICD-11 to another.
Keeping in mind also that most adenoma do not progress, and some regress. For example, at autopsy at least 30-40% of people have adenomas, and the adenoma detection rarte in 40 year olds is 30% or more, yet 30% of people do not get colon cancer, and that was true before colonoscopies.
That study should have never been funded.
The VA likely funded it based on the influence of a key UCSD-administrator (Vice-Chancellor for Health Sciences), probably as a bonus check for past service (is that about right, Dr Carethers).
The data highlight competing mortality risk, especially in older adults, but this should refine rather than dismiss screening. Evidence shows colorectal screening lowers cancer incidence and mortality, so decisions should be individualized based on age, comorbidity, and life expectancy rather than a single risk comparison.
A better heuristic is to ignore what tests are available in the marketplace and identify your own top tier health risks and address those through 1. Lifestyle 2. Medications (if needed) 3. Specific testing. With #1 separated by 10 miles from #2, which is a mile apart from #3.
I think this whole argument leans too heavily on the wrong endpoint.
Mortality doesn’t capture what colon cancer actually does to people.
In my world, colorectal cancer isn’t just about whether someone dies at 10 years. It’s everything that comes with it. I see patients whose cancers were found early on screening and they’re done with a polyp removal or a straightforward surgery. I also see the other side. Big operations, ostomies, chemo, neuropathy, years of follow up, and a life that looks very different even if they’re technically “alive” at the end of it.
Those two scenarios are treated the same if you’re only looking at mortality. That’s the problem.
The other piece is that colonoscopy isn’t just detecting cancer. It’s preventing it. When you remove an adenoma, you’re changing whether that patient ever has to go through any of this at all. That doesn’t show up well in a mortality ratio, especially over a 10 year window.
So when we start saying things like “you’re 96 times more likely to die of something else,” it sounds convincing, but it’s really answering a different question. It’s comparing causes of death at a population level. It’s not asking what happens to the individual patient if this cancer shows up and whether we could have prevented it.
How about an endpoint like “Can this help you avoid becoming a cancer patient in the first place, or at least make that experience a lot life altering if it happens?”
It isn't all about one actuarial metric of lifespan. Advanced colon cancer is a grim way to spend ones last years. And early-stage colon cancer very often be addressed successfully simply by snipping polyps. Or surgical intervention that, while more iinvasive, is still relatively minor compared to being fitted with a colostomy bag. Or the prospect of dying in agony without treatment.
By contrast, conditions like COPD and congestive heart failure, undeniably more common as a cause of death, aren't really amenable to any reversal of the condition by any intervention, surgical or otherwise. Lifespan can be extended with medications and oxygen tanks. These conditions are tragedies, but they take the form of a slowly creeping decline toward a final demise, compared to the intractable pain and disability found in many cases of inoperable malignant tumors.
Monetary expense also has to be mentioned: how many colonoscopies can be done for the cost of one major surgery and follow-up for a case of advanced bowel cancer? Or should "we" simply euthanize people over 75, if they're found with advanced colon cancer?
Even given the current standard cost range for colonoscopies*, how are they not a bargain, given that even a procedure that finds and removes precancerous or cancerous polyps isn't remotely as invasive, costly, and exhausting to monetary resources and physical reserves as major inpatient bowel surgery with a lengthy follow-up of a chemotherapy and/or radiation treatment regime?
[*$2,000-$4,000 baseline; the cost is typically much more when insurance is billed, which everyone accepts as taken for granted, although nonetheless mystifying.]
Voluntary euthanasia is the solution to advanced colon cancer. If you offered people a luxury overseas holiday in exchange for euthenasia (funded by all the money that's saved in end of life care) some of us would be thrilled.
Of Modest Proposals and Transactional Desire in the Modern World
"How does it make sense to look for one disease when you are 36-90 times more likely to die from something else. I am asking. Tell me."
Because it reduces my risk of dying by 1% to 2.7%.
Would you put a 91-chamber revolver to your head with a bullet in one chamber, spin the barrel, and pull the trigger? How about a 37-chamber revolver?
I bet no.
And what if we could ALSO screen for some or all of those other causes? Would you not do that, because any one of them only has a small chance of killing you?
Most sensible comment in this thread.
By MarkS
I think the main takeaway point is that this would be a personal decision that rational people would decide very differently. We need to inject some more personalized and data-driven information so that patients are best able to make their own decisions. Some people will hear that they can decrease their risk of something that they have a 2-3% chance of developing over the next 10 years and they will jump at the opportunity - they'll get the colonoscopy. Other people will hear that they have that chance and will say they have no interest in spending time, effort, money on screening for something they have a 2% risk of. People have vastly differing values.
what our current system does is strong arm all people into getting screened. We don't give them hard data on their risk and by how much said screening might reduce it.
We've been given a box to check and we want to check it. Again, main point being this attitude (driven by quality metrics and other external forces) highly inflates how effective these tests are and inflates each person's actual risk of the condition.
That is not to say that nobody should be screened - but recognize and admit what the benefits generally would be.
Yes, I completely agree.