This study reminds me that colon cancer screening is a decision, like all healthcare decisions, to be made by a patient in consultation with his or her physician.
"Colonoscopy actually prevents cancer. A precancerous polyp that is removed poses no threat of mutating/growing into a cancer."
How do you know that the precancerous polyp is not just a manifestation of an underlying cancer, in which case its removal may only slightly mitigate the risk for future disease.
What is the rate of conversion of precancerous polyps to cancerous? Do we have any idea? My old dermatologist used to say “the only good mole is a gone mole” and he made a lot of money through sharing that message with his patients. Unfortunately, he missed melanoma on my friend and it was not associated with a mole!
Surely you have seen harms from colonsocopy during your career? I know I have. Perforations requiring surgery. No deaths that I am aware of. but the cost is huge and that is a potential harm if those resources of money and time were spent elewhere. Also, why compare colonoscopy to doing nothing. Isnt the comparison to sigmoidoscopy or FIT test?
My brother-in-law had a perforation from a colonoscopy a year ago. He was very sick, in the hospital for two weeks, at a cost of several hundred thousand dollars. These risks need to be accounted for in the analysis. A minor point: with a risk reduction ratio of 0.31%, isn't the number to screen the inverse: 323?
Related question popped up for me - is there a way to learn if a health system grades their docs on screening compliance? I changed insurance & health systems (from Kaiser to UW) over the past couple of years and the mammogram guidance to me personally in conversation has differed (still "shared decision-making" but I definitely felt persuaded in different directions). Most recently I agreed to the referral but haven't scheduled - and I'm even getting follow up texts, notes in MyChart, calls. Would love to know if part of the "encouragement" to screen is to meet quotas. I have lower than average risk per various assessments.
Per your comment: “ For those of you who like the “number needed to screen.” These numbers equate to a number needed to screen of 263 to prevent one colon cancer. For a patient, there is a 1/263 chance that your colonoscopy will prevent a cancer.”
263 x $3000 average cost/charge = $789000 or put another way, over $$3/4 of a million dollars all burdened on the taxpayer (Medicare/Medicaid) and/or the insurance premium “payer”.
The studies we need are how to reduce the overall cost burden and actually support/protect patient’s quality life years through lower cost, equally effective “screening “ tools/tests/screening algorithms.
Also not considered here are the patient’s costs as well (prep, lost work, general productivity declines for days, family burden, emotional, etc).
We all want perfect health, and allopathic medicine promises to provide the illusion that it’s possible with all the magic elixirs of “modern” medicine.
My bias of course is I’m medically conservative and also look at cost to benefits (maybe too much).
"I am an avowed medical conservative who thinks that a doctor’s role is primarily to treat disease."
I winced at that statement. I don't want a doctor--any doctor--to _primarily_ treat my disease. I want the doctor to primarily seek to understand and fix or improve the underlying cause(s), and only secondarily treat the disease/condition, either in the interim or because the underlying cause isn't treatable. In any case, in addition to standard medical interventions, I want the practitioner to work toward whole-body health with diet, lifestyle, and nutrients - not just with drugs and endless tests.
Unfortunately, education in diet, lifestyle, and nutrients is woefully lacking in medical schools, and most practitioners are not only uneducated in these interventions, but also unsympathetic, even hostile, to patients who research and implement such approaches on their own. I strongly advocate the integrative approach--taking the best of both worlds, and neither one to the exclusion to the other.
I feel exactly the opposite, I want a doctor who is focused on treating disease. That's where the huge benefit of medicine lies, in helping a patient who actually has a PROBLEM.
That depends on what the "problem" is. What about the many problems that can be mitigated without requiring lifetime of drug intervention, with all their attendant known side effects? If it's something that diet and lifestyle changes can improve (e.g., diabetes, osteopenia, elevated cholesterol, high blood pressure), why throw PPIs, bisphosphonates, statins, and hypertension drugs at it for life instead of addressing the causes? Both approaches may be needed until the condition improves, or even long term but at reduced Rx dosages. My post stated that if it can't be mitigated, treatment is the obvious choice. Even in bone fractures (granted not a disease), there are nutrients that help bones heal and reduce non-union that can be used along side and in conjunction with the critical care and follow-up fractures require.
In my opinion, being "focused on treating disease" should include _all_ possible beneficial treatments, not just allopathic ones, but unfortunately integrative care is often treated as the ugly step-sister and not allowed into the room. Fortunately I have a PCP and even some specialists who welcome (or tolerate) the integrative approach, and both my husband and I have significantly benefited.
Why not do cologard for general screening, then build a case for more invasive procedures if family history and risk factors (smoking, obesity etc) are present? I appreciate the polyp argument but not all polyps become cancerous. It seems that the point of the recent study was that colonoscopy, as a one-size-fits-all approach, is not warranted.
It is evident that your patients trust and respect you, Dr. Cifu, and that is to your credit.
I am curious as to your opinion on Cologuard for younger, low risk patients who are considering postponing or foregoing colonoscopy due to prep/schedule/anesthesia or other concerns, clearly as just a true screening test. Thoughts?
Why Cologuard instead of a FIT test? It's WAY more expensive, more involved than a FIT test, and only reached effectiveness by combining the DNA with a FIT test at a much higher cost.
My understanding is that Cologuard is still more sensitive than immunochemical testing at picking up CA, but does have a higher false positive rate to consider. Clearly, cost might be a factor for some patients, though it is only recommended every three years. (FIT is advised to be done yearly.). We do lots of stool testing in my clinic, (pediatrics), and obtaining a full specimen hasn't been a problem.
The writer states "I am an avowed medical conservative who thinks that a doctor’s role is primarily to treat disease.[i] Anything that has the potential of turning a healthy person into a patient should be examined in a very bright light." Then why doesn't she and all doctors tell patients to remove meat and refined food from their diet since they are a strong contributors to colon cancer.
Colon cancer is the second-leading cause of cancer death in the United States, behind lung cancer. At least 70% of colon cancer cases are avoidable. Numerous studies suggest that a plant-based diet may be beneficial in the prevention, treatment, and even reversal of cancer.
What may contribute to colon cancer?
Heterocyclic amines, carcinogens created by cooking muscle tissue, are associated with colon cancer, as are dangerous compounds called nitrosamines found in cured meats. Too much iron in the body, especially the type of iron that comes from meat, may also increase the risk of colon cancer. Animal protein consumption is associated with an increase in a cancer-promoting growth hormone called IGF-1. High saturated fat from animal products stimulates elevated levels of bile acids, which have been shown to be cancer-causing. When animal protein putrefies in the colon, ammonia is produced, which is associated with cancer risk. Poultry and other animal products contain viruses that are known to cause cancer in animals and may be passed to humans. Additionally, dioxins in fish and eggs may contribute to colon cancer risk.
What may help prevent colon cancer?
The rarity of colon cancer in Africans is attributable to very low animal-product consumption. The significantly lower pH in the colon resulting from a plant-based diet helps lower the risk of colon cancer. Specific protective foods include beans, berries (including Indian gooseberries and organic strawberries), broccoli, black beans, a number of herbal varieties of tea, carob, coffee, apples, turmeric, cranberries, sweet potatoes, nuts, and lemon rind and seeds. Vitamin D may also play a role in preventing colon cancer. The kind of “resistant starch” that comes from plant foods like cooked beans, peas, lentils, and raw oatmeal—can block the accumulation of potentially harmful byproducts of animal-protein metabolism in the colon.
Stool size may be an important factor in colon cancer prevention. A plant-based diet produces the healthiest stools, and leads to consistently larger bowel movements.
While randomized controlled trials are highly reliable in assessing interventions like drugs, they’re harder to do with diet. Dietary diseases can take decades to develop. It’s not like you can give people placebo food, and it’s hard to get people to stick to assigned diets, especially for the years it would take to observe effects on hard endpoints like heart disease or colon cancer. That’s why observational studies of large numbers of people and their diets over time are used to see which foods appear to be linked to which diseases. If you compare data obtained from observational population studies versus randomized trials, on average, there is little evidence for significant differences between the findings. Not just in the same direction of effect, but of the same general magnitude of the effect, in about 90 percent of the treatments they looked at. We don’t need the same level of certainty telling someone to eat more broccoli or less meat, compared to whether or not you want to prescribe someone some drug. After all, prescription drugs are the third leading cause of death in the United States. It goes heart disease, cancer, then doctors. About 100,000 Americans are wiped out every year from the side effects of prescription drugs taken as directed or some procedures instead of prevention. So, given the massive risks, you better have rock-solid evidence that there are benefits that outweigh the risks. Randomized double-blind, placebo-controlled trials for drugs, absolutely, but when you’re just telling people to cut down on doughnuts or cured meat, you don’t need the same level of proof.
The industry-funded sugar paper concluding that the dietary guidelines telling people to cut down aren’t trustworthy, because they’re based on such “low-quality evidence,” is an example of the inappropriate use of the drug trial paradigm in nutrition research. NutriGrade, a scoring system specifically designed to assess and judge the level of evidence in nutrition research, is the standard, not RCT.
One of the things about NutriGrade is that it specifically takes funding bias into account, so industry-funded trials are downgraded—no wonder the industry-funded authors chose the inappropriate drug method instead. HEALM is another one, Hierarchies of Evidence Applied to Lifestyle Medicine, specifically designed because existing tools such as GRADE are not viable options when it comes to questions that you can’t fully address through randomized controlled trials (RCTs). Each research method has its unique contribution. In a lab, you can explore the exact mechanisms, RCTs can prove cause and effect, and huge population studies can study hundreds of thousands of people at a time for decades.
THERE are randomized controlled trials showing trans fats increased risk factors for heart disease, and we had population studies showing that the more trans fats people ate, the more heart disease they had. So, taken together, these studies forged a strong case for the harmful effects of trans fat consumption on heart disease, and as a consequence, it was largely removed from the U.S. food supply, preventing as many as 200,000 heart attacks every year. Now, it’s true that we never had randomized controlled trials looking at hard endpoints, like heart attacks and death, because that would take years of randomizing people to eat like canisters of Crisco every day. You can’t let the perfect be the enemy of the good when there are tens of thousands of lives at stake.
Even if RCTs are unavailable or impossible to conduct, there is plenty of evidence from observational studies on the nutritional causes of many cancers, such as on red meat increasing the risk of colorectal cancer. So, if dietary guidelines aiming at cancer prevention were to be assessed with the drug-designed GRADE approach, they’d reach the same conclusion that the sugar paper did—low quality evidence. And so, it’s no surprise a meat-industry-funded institution hired the same person who helped conceive and design the sugar-industry funded study. And boom, lead author saying we can ignore the dietary guidelines to reduce red and processed meat consumption, because they used GRADE methods to rate the certainty of evidence, and though current dietary guidelines recommend limiting meat consumption, their results predictably demonstrated that the evidence was of low quality.
I appreciate your well thought out comment. Point taken. But saying something like no RCT is just an opinion which are a dime a dozen. Arguments based on evidence and examples are needed to make opinions useful. At least that is what the emails I got thanking me for my "lot of words," suggests.
As an oncologist, I value this nuanced approach. We should also not forget that a flexible sigmoidoscopy is a reasonable, less costly and convenient option. Earlier studies have supported the likelihood that screening benefits arise from finding left sided colon lesions, which is what a flex sig does.
The RCT clearly shows we do not fully understand all of the factors impacting overall mortality. The non-significant difference in colon cancer death is particularly telling - how could this be? Is it possible that the procedure accelerates this outcome in a similar fraction of patients as it prevents? To improve either the procedure itself, or overall care, this should study should be viewed as a challenge to find the answer.
Very good point. All-cause mortality is the key. And we know that in the elderly population, competing causes of death are such that it's often impossible to clearly assign a person's demise to a single factor.
As to Dr. Cifu's defense of colon cancer screening, my own take is that 'screening' is a marketing term. A promotional term. A term that is reassuring for patients. The medical industry knows this.
Thus millions of people literally buy the idea that colonoscopies, PSA tests, covid tests, mammographies, bone density tests, etc. will provide 'peace of mind', or 'catch it early'. And insurance companies tend to string along.
The whole medical landscape might be different If doctors and medical associations ditched the 'screening' motif, and, talked bluntly about true benefits and true risks, without sweetening the messages and promoting the products.
For example, re colonoscopies a doctor might simply point out
- A colonoscopy doesn't guarantee that you won't die of colon cancer. In fact, it doesn't guarantee anything.
- It is an intervention that will occasionally be harmful or even fatal for a patient.
- And statistics indicate that people who have colonoscopies don't live longer than people who never get colonoscopies.
But usually, all a patient gets is reassuring words from the doc, plus a fine print legal document absolving the doc from responsibility if anything goes wrong.
Of course, I'm all for patients making their own decisions about treatments and interventions. Thus if a patient is so worried about colon cancer that they want a colonoscopy, fine. It's their choice.
But hey, let's not try to bring everyone into the net, and let's not give everyone false ideas about the ultimate efficacy of this or that treatment or intervention.
Another issue which has not been addressed in this whole debate is how often to screen - I recall a physician I worked with saying that he believed that if a person had a full colonoscopy at age 50 that it did not need to be repeated. I also read some research that if a person had all polyps removed that there was no evidence that their risk was any different than another person that had no polyps (absent any hereditary condition).
I am a survivor because I did get screened and a mass was discovered. Over many years I received yearly colonoscopies where polyps were always found; then came my routine visit where aggressive cancer was found. The adjutant follow-up treatment was only tolerable for four months instead of the desired six. I can assure anybody that the treatment was much more debilitating than any of the exams. There were times I was incapable of any real functioning and became quite dehydrated requiring hours of additional infusions. I can understand why some cancer survivors refuse treatment should a another cancer return. I'm left with kidney damage and a degree of neuropathy in my fingers and toes after the treatments. OTOH, I'm now 12 years out and at 82 maybe being given a few more years to go.
What strikes me about the colonoscopy debate is that we wouldn't be having it if the cost were trivial and the procedure no more cumbersome or arduous than a blood draw. From a population perspective, I suspect that the impact of colonoscopy is rather small and this doesn't require an RCT to show this. Indeed Adam Cifu's figure that you have to colonoscopy 250 patients to detect 1 premalignant polyp or cancer is indicative of that. However, from an individual's perspective, one has to look at things in a different way and assess the pros and cons as related to ones personal circumstances and preferences. For myself, I would opt for a colonoscopy every 5 years and a FOBT every year. Of course, I would far prefer it if the prep required for a colonoscopy was as minimal as for a flex sig. Because lets' face it, the only bad thing about a colonoscopy is the prep which quite frankly is absolutely disgusting. From my perspective, I don't mind the pooping from midnight through 6 am, but just drinking the prep is really really hard and nausea inducing.
The other key issue regarding colonoscopy, and for that matter flex sig, is that the outcomes and pick up rate are going to be very operator dependent. Perhaps this could be improved by continuously recording the colonoscopy and then subjecting it to subsequent AI analysis as well as analysis by an independent examiner. In other words, colonoscopy/flex sig is not equivalent to a blood test that requires minimal/no human intervention to carry out and whose interpretation is entirely straightforward.
Your point about costs is pivotal. The most astonishing thing I learned when I was involved in examining claims for colonoscopies is that a single insurer was paying FIVE BILLION excess dollars out each year because these were being done as "hospital outpatients" (HOPD) rather than as "real" outpatients. The care/exam are exactly the same -- but the cost is an order of magnitude higher.
Hospitals force this on the system and physicians who should have the general interest of patients/the health system in mind ignore it because they get paid the same irrespective. There is (for one insurer) FIVE BILLION DOLLARS that could be spent on better health care being paid as coerced funds to hospitals.
Every procedure that can be done as an outpatient is subject to this abuse and most of us doctors know it -- but even jaded I was shocked at the magnitude of this rip-off. The more affordable any procedure is, the more likely it will be properly applied since one of the decision factors comes off the table.
No discussion of this entire area is complete without considering this. Most health care decisions are cost/benefit decisions -- not all the costs (or benefits) are financial, of course, but the abuse of the financial ones skews the curve dramatically -- and never in the direction of the patient.
"Colonoscopy actually prevents cancer. A precancerous polyp that is removed poses no threat of mutating/growing into a cancer."
How do you know that the precancerous polyp is not just a manifestation of an underlying cancer, in which case its removal may only slightly mitigate the risk for future disease.
What is the rate of conversion of precancerous polyps to cancerous? Do we have any idea? My old dermatologist used to say “the only good mole is a gone mole” and he made a lot of money through sharing that message with his patients. Unfortunately, he missed melanoma on my friend and it was not associated with a mole!
Surely you have seen harms from colonsocopy during your career? I know I have. Perforations requiring surgery. No deaths that I am aware of. but the cost is huge and that is a potential harm if those resources of money and time were spent elewhere. Also, why compare colonoscopy to doing nothing. Isnt the comparison to sigmoidoscopy or FIT test?
My brother-in-law had a perforation from a colonoscopy a year ago. He was very sick, in the hospital for two weeks, at a cost of several hundred thousand dollars. These risks need to be accounted for in the analysis. A minor point: with a risk reduction ratio of 0.31%, isn't the number to screen the inverse: 323?
Related question popped up for me - is there a way to learn if a health system grades their docs on screening compliance? I changed insurance & health systems (from Kaiser to UW) over the past couple of years and the mammogram guidance to me personally in conversation has differed (still "shared decision-making" but I definitely felt persuaded in different directions). Most recently I agreed to the referral but haven't scheduled - and I'm even getting follow up texts, notes in MyChart, calls. Would love to know if part of the "encouragement" to screen is to meet quotas. I have lower than average risk per various assessments.
So, some easy math here.
Per your comment: “ For those of you who like the “number needed to screen.” These numbers equate to a number needed to screen of 263 to prevent one colon cancer. For a patient, there is a 1/263 chance that your colonoscopy will prevent a cancer.”
263 x $3000 average cost/charge = $789000 or put another way, over $$3/4 of a million dollars all burdened on the taxpayer (Medicare/Medicaid) and/or the insurance premium “payer”.
The studies we need are how to reduce the overall cost burden and actually support/protect patient’s quality life years through lower cost, equally effective “screening “ tools/tests/screening algorithms.
Also not considered here are the patient’s costs as well (prep, lost work, general productivity declines for days, family burden, emotional, etc).
We all want perfect health, and allopathic medicine promises to provide the illusion that it’s possible with all the magic elixirs of “modern” medicine.
My bias of course is I’m medically conservative and also look at cost to benefits (maybe too much).
"I am an avowed medical conservative who thinks that a doctor’s role is primarily to treat disease."
I winced at that statement. I don't want a doctor--any doctor--to _primarily_ treat my disease. I want the doctor to primarily seek to understand and fix or improve the underlying cause(s), and only secondarily treat the disease/condition, either in the interim or because the underlying cause isn't treatable. In any case, in addition to standard medical interventions, I want the practitioner to work toward whole-body health with diet, lifestyle, and nutrients - not just with drugs and endless tests.
Unfortunately, education in diet, lifestyle, and nutrients is woefully lacking in medical schools, and most practitioners are not only uneducated in these interventions, but also unsympathetic, even hostile, to patients who research and implement such approaches on their own. I strongly advocate the integrative approach--taking the best of both worlds, and neither one to the exclusion to the other.
I feel exactly the opposite, I want a doctor who is focused on treating disease. That's where the huge benefit of medicine lies, in helping a patient who actually has a PROBLEM.
That depends on what the "problem" is. What about the many problems that can be mitigated without requiring lifetime of drug intervention, with all their attendant known side effects? If it's something that diet and lifestyle changes can improve (e.g., diabetes, osteopenia, elevated cholesterol, high blood pressure), why throw PPIs, bisphosphonates, statins, and hypertension drugs at it for life instead of addressing the causes? Both approaches may be needed until the condition improves, or even long term but at reduced Rx dosages. My post stated that if it can't be mitigated, treatment is the obvious choice. Even in bone fractures (granted not a disease), there are nutrients that help bones heal and reduce non-union that can be used along side and in conjunction with the critical care and follow-up fractures require.
In my opinion, being "focused on treating disease" should include _all_ possible beneficial treatments, not just allopathic ones, but unfortunately integrative care is often treated as the ugly step-sister and not allowed into the room. Fortunately I have a PCP and even some specialists who welcome (or tolerate) the integrative approach, and both my husband and I have significantly benefited.
Unfortunately I don't think the doctor can treat poverty which is the greatest cause of disease and ill health globally.
@Phyllis Agree 100%.
That is your job as the patient, not the doctors job. Allopathic healthcare only treats disease, and never considers causes. It also never will.
Why not do cologard for general screening, then build a case for more invasive procedures if family history and risk factors (smoking, obesity etc) are present? I appreciate the polyp argument but not all polyps become cancerous. It seems that the point of the recent study was that colonoscopy, as a one-size-fits-all approach, is not warranted.
It is evident that your patients trust and respect you, Dr. Cifu, and that is to your credit.
I am curious as to your opinion on Cologuard for younger, low risk patients who are considering postponing or foregoing colonoscopy due to prep/schedule/anesthesia or other concerns, clearly as just a true screening test. Thoughts?
Why Cologuard instead of a FIT test? It's WAY more expensive, more involved than a FIT test, and only reached effectiveness by combining the DNA with a FIT test at a much higher cost.
My understanding is that Cologuard is still more sensitive than immunochemical testing at picking up CA, but does have a higher false positive rate to consider. Clearly, cost might be a factor for some patients, though it is only recommended every three years. (FIT is advised to be done yearly.). We do lots of stool testing in my clinic, (pediatrics), and obtaining a full specimen hasn't been a problem.
The writer states "I am an avowed medical conservative who thinks that a doctor’s role is primarily to treat disease.[i] Anything that has the potential of turning a healthy person into a patient should be examined in a very bright light." Then why doesn't she and all doctors tell patients to remove meat and refined food from their diet since they are a strong contributors to colon cancer.
Tom, because that is not accurate.
Colon cancer is the second-leading cause of cancer death in the United States, behind lung cancer. At least 70% of colon cancer cases are avoidable. Numerous studies suggest that a plant-based diet may be beneficial in the prevention, treatment, and even reversal of cancer.
What may contribute to colon cancer?
Heterocyclic amines, carcinogens created by cooking muscle tissue, are associated with colon cancer, as are dangerous compounds called nitrosamines found in cured meats. Too much iron in the body, especially the type of iron that comes from meat, may also increase the risk of colon cancer. Animal protein consumption is associated with an increase in a cancer-promoting growth hormone called IGF-1. High saturated fat from animal products stimulates elevated levels of bile acids, which have been shown to be cancer-causing. When animal protein putrefies in the colon, ammonia is produced, which is associated with cancer risk. Poultry and other animal products contain viruses that are known to cause cancer in animals and may be passed to humans. Additionally, dioxins in fish and eggs may contribute to colon cancer risk.
What may help prevent colon cancer?
The rarity of colon cancer in Africans is attributable to very low animal-product consumption. The significantly lower pH in the colon resulting from a plant-based diet helps lower the risk of colon cancer. Specific protective foods include beans, berries (including Indian gooseberries and organic strawberries), broccoli, black beans, a number of herbal varieties of tea, carob, coffee, apples, turmeric, cranberries, sweet potatoes, nuts, and lemon rind and seeds. Vitamin D may also play a role in preventing colon cancer. The kind of “resistant starch” that comes from plant foods like cooked beans, peas, lentils, and raw oatmeal—can block the accumulation of potentially harmful byproducts of animal-protein metabolism in the colon.
Stool size may be an important factor in colon cancer prevention. A plant-based diet produces the healthiest stools, and leads to consistently larger bowel movements.
and the link to the RCT?
While randomized controlled trials are highly reliable in assessing interventions like drugs, they’re harder to do with diet. Dietary diseases can take decades to develop. It’s not like you can give people placebo food, and it’s hard to get people to stick to assigned diets, especially for the years it would take to observe effects on hard endpoints like heart disease or colon cancer. That’s why observational studies of large numbers of people and their diets over time are used to see which foods appear to be linked to which diseases. If you compare data obtained from observational population studies versus randomized trials, on average, there is little evidence for significant differences between the findings. Not just in the same direction of effect, but of the same general magnitude of the effect, in about 90 percent of the treatments they looked at. We don’t need the same level of certainty telling someone to eat more broccoli or less meat, compared to whether or not you want to prescribe someone some drug. After all, prescription drugs are the third leading cause of death in the United States. It goes heart disease, cancer, then doctors. About 100,000 Americans are wiped out every year from the side effects of prescription drugs taken as directed or some procedures instead of prevention. So, given the massive risks, you better have rock-solid evidence that there are benefits that outweigh the risks. Randomized double-blind, placebo-controlled trials for drugs, absolutely, but when you’re just telling people to cut down on doughnuts or cured meat, you don’t need the same level of proof.
The industry-funded sugar paper concluding that the dietary guidelines telling people to cut down aren’t trustworthy, because they’re based on such “low-quality evidence,” is an example of the inappropriate use of the drug trial paradigm in nutrition research. NutriGrade, a scoring system specifically designed to assess and judge the level of evidence in nutrition research, is the standard, not RCT.
One of the things about NutriGrade is that it specifically takes funding bias into account, so industry-funded trials are downgraded—no wonder the industry-funded authors chose the inappropriate drug method instead. HEALM is another one, Hierarchies of Evidence Applied to Lifestyle Medicine, specifically designed because existing tools such as GRADE are not viable options when it comes to questions that you can’t fully address through randomized controlled trials (RCTs). Each research method has its unique contribution. In a lab, you can explore the exact mechanisms, RCTs can prove cause and effect, and huge population studies can study hundreds of thousands of people at a time for decades.
THERE are randomized controlled trials showing trans fats increased risk factors for heart disease, and we had population studies showing that the more trans fats people ate, the more heart disease they had. So, taken together, these studies forged a strong case for the harmful effects of trans fat consumption on heart disease, and as a consequence, it was largely removed from the U.S. food supply, preventing as many as 200,000 heart attacks every year. Now, it’s true that we never had randomized controlled trials looking at hard endpoints, like heart attacks and death, because that would take years of randomizing people to eat like canisters of Crisco every day. You can’t let the perfect be the enemy of the good when there are tens of thousands of lives at stake.
Even if RCTs are unavailable or impossible to conduct, there is plenty of evidence from observational studies on the nutritional causes of many cancers, such as on red meat increasing the risk of colorectal cancer. So, if dietary guidelines aiming at cancer prevention were to be assessed with the drug-designed GRADE approach, they’d reach the same conclusion that the sugar paper did—low quality evidence. And so, it’s no surprise a meat-industry-funded institution hired the same person who helped conceive and design the sugar-industry funded study. And boom, lead author saying we can ignore the dietary guidelines to reduce red and processed meat consumption, because they used GRADE methods to rate the certainty of evidence, and though current dietary guidelines recommend limiting meat consumption, their results predictably demonstrated that the evidence was of low quality.
That's a lot of words to say no RCT.
I appreciate your well thought out comment. Point taken. But saying something like no RCT is just an opinion which are a dime a dozen. Arguments based on evidence and examples are needed to make opinions useful. At least that is what the emails I got thanking me for my "lot of words," suggests.
As an oncologist, I value this nuanced approach. We should also not forget that a flexible sigmoidoscopy is a reasonable, less costly and convenient option. Earlier studies have supported the likelihood that screening benefits arise from finding left sided colon lesions, which is what a flex sig does.
I am on team Cifu.
The RCT clearly shows we do not fully understand all of the factors impacting overall mortality. The non-significant difference in colon cancer death is particularly telling - how could this be? Is it possible that the procedure accelerates this outcome in a similar fraction of patients as it prevents? To improve either the procedure itself, or overall care, this should study should be viewed as a challenge to find the answer.
Very good point. All-cause mortality is the key. And we know that in the elderly population, competing causes of death are such that it's often impossible to clearly assign a person's demise to a single factor.
As to Dr. Cifu's defense of colon cancer screening, my own take is that 'screening' is a marketing term. A promotional term. A term that is reassuring for patients. The medical industry knows this.
Thus millions of people literally buy the idea that colonoscopies, PSA tests, covid tests, mammographies, bone density tests, etc. will provide 'peace of mind', or 'catch it early'. And insurance companies tend to string along.
The whole medical landscape might be different If doctors and medical associations ditched the 'screening' motif, and, talked bluntly about true benefits and true risks, without sweetening the messages and promoting the products.
For example, re colonoscopies a doctor might simply point out
- A colonoscopy doesn't guarantee that you won't die of colon cancer. In fact, it doesn't guarantee anything.
- It is an intervention that will occasionally be harmful or even fatal for a patient.
- And statistics indicate that people who have colonoscopies don't live longer than people who never get colonoscopies.
But usually, all a patient gets is reassuring words from the doc, plus a fine print legal document absolving the doc from responsibility if anything goes wrong.
Of course, I'm all for patients making their own decisions about treatments and interventions. Thus if a patient is so worried about colon cancer that they want a colonoscopy, fine. It's their choice.
But hey, let's not try to bring everyone into the net, and let's not give everyone false ideas about the ultimate efficacy of this or that treatment or intervention.
Another issue which has not been addressed in this whole debate is how often to screen - I recall a physician I worked with saying that he believed that if a person had a full colonoscopy at age 50 that it did not need to be repeated. I also read some research that if a person had all polyps removed that there was no evidence that their risk was any different than another person that had no polyps (absent any hereditary condition).
Very interesting!
I am a survivor because I did get screened and a mass was discovered. Over many years I received yearly colonoscopies where polyps were always found; then came my routine visit where aggressive cancer was found. The adjutant follow-up treatment was only tolerable for four months instead of the desired six. I can assure anybody that the treatment was much more debilitating than any of the exams. There were times I was incapable of any real functioning and became quite dehydrated requiring hours of additional infusions. I can understand why some cancer survivors refuse treatment should a another cancer return. I'm left with kidney damage and a degree of neuropathy in my fingers and toes after the treatments. OTOH, I'm now 12 years out and at 82 maybe being given a few more years to go.
Wait you had colonoscopies for years and then an aggressive cancer was discovered? Was it colon cancer? May you live to a joyful 100.
thanks. doubt a 100 but maybe a few more. I have been quiet lucky and am grateful. Pray for one more, if in the plan
What strikes me about the colonoscopy debate is that we wouldn't be having it if the cost were trivial and the procedure no more cumbersome or arduous than a blood draw. From a population perspective, I suspect that the impact of colonoscopy is rather small and this doesn't require an RCT to show this. Indeed Adam Cifu's figure that you have to colonoscopy 250 patients to detect 1 premalignant polyp or cancer is indicative of that. However, from an individual's perspective, one has to look at things in a different way and assess the pros and cons as related to ones personal circumstances and preferences. For myself, I would opt for a colonoscopy every 5 years and a FOBT every year. Of course, I would far prefer it if the prep required for a colonoscopy was as minimal as for a flex sig. Because lets' face it, the only bad thing about a colonoscopy is the prep which quite frankly is absolutely disgusting. From my perspective, I don't mind the pooping from midnight through 6 am, but just drinking the prep is really really hard and nausea inducing.
The other key issue regarding colonoscopy, and for that matter flex sig, is that the outcomes and pick up rate are going to be very operator dependent. Perhaps this could be improved by continuously recording the colonoscopy and then subjecting it to subsequent AI analysis as well as analysis by an independent examiner. In other words, colonoscopy/flex sig is not equivalent to a blood test that requires minimal/no human intervention to carry out and whose interpretation is entirely straightforward.
Your point about costs is pivotal. The most astonishing thing I learned when I was involved in examining claims for colonoscopies is that a single insurer was paying FIVE BILLION excess dollars out each year because these were being done as "hospital outpatients" (HOPD) rather than as "real" outpatients. The care/exam are exactly the same -- but the cost is an order of magnitude higher.
Hospitals force this on the system and physicians who should have the general interest of patients/the health system in mind ignore it because they get paid the same irrespective. There is (for one insurer) FIVE BILLION DOLLARS that could be spent on better health care being paid as coerced funds to hospitals.
Every procedure that can be done as an outpatient is subject to this abuse and most of us doctors know it -- but even jaded I was shocked at the magnitude of this rip-off. The more affordable any procedure is, the more likely it will be properly applied since one of the decision factors comes off the table.
No discussion of this entire area is complete without considering this. Most health care decisions are cost/benefit decisions -- not all the costs (or benefits) are financial, of course, but the abuse of the financial ones skews the curve dramatically -- and never in the direction of the patient.