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Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

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Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#101

Post by [deleted] »

ricardobeat wrote: post #43
hef19898 wrote: post #34

Earlier quoted context omitted.

Invited or not, if you don't show up to a colonoscopy you don't get one. Which means the study's data on invitations alone cannot be used to evaluate the effect of colonoscopies. Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies. Argueing about the randomization of these numbers, and the meta-statistical aspects o…

You have to look at it from the perspective of medical practice. The hypothesis is that inviting people for a regular check up reduces mortality. If a lot of people don’t take up the offer because the procedure is too invasive, carries some risk, etc. then that is a very relevant variable to take into account. Vs, for example, fecal testing as mentioned in the article. It could have a lower precision, but if uptake i…

[deleted]

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#102

Post by BenoitEssiambre »

ricardobeat wrote: post #29
em500 wrote: post #27

Several posters have criticized the title of the news article "In gold-standard trial, colonoscopy fails to reduce rate of cancer deaths". The actual study is titled "Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death" [1] The authors conclude that "In this randomized trial, the risk of colorectal cancer at 10 years was lower among participants who were invited to undergo screening colono…

There is nothing wrong with the title. The study failed to find a reduction in death rate despite lowering the incidence of cancer, and that is the center of the piece. It goes into detail of why this is surprising. The study authors were interviewed and agreed. The reporting actually adds a lot of context that you would never get from a link to a random study. Like, for example, how it is called the “gold standard”…

That is incorrect. The title is completely wrong.

"Study failed to find a reduction" _does not equal_ "There wasn't a reduction".

From the abstract: "The risk of death from colorectal cancer was 0.28% in the invited group and 0.31% in the usual-care group (risk ratio, 0.90; 95% CI, 0.64 to 1.16)"

Look at the confidence interval. This study was both consistent with a 36% reduction in deaths or a 16% increase in deaths. It's just a really wide range. All we can say about this study is that it didn't gather enough data to identify the size of the effect, not that there wasn't an effect.

This is likely because there wasn't that many people who died of colon cancer in any of the groups. This study just didn't track enough people to provide an answer.

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#103

Post by refurb »

eecc wrote: post #92
refurb wrote: post #86

Earlier quoted context omitted.

Yeah, it's pretty complicated. I'm not that surprised death rates were similar. Colonoscopies will catch pre-cancerous masses like polyps, so I can see the cancer rate being lower. But if diagnosed with cancer, treatments are quite good for colorectal cancer, so you may not see that much of a difference in death rate on a 10 year horizon.

Well then the title is indeed misleading. It's not the colonoscopy that's failing to reduce cancer death rates, treatments are. Indeed the title should have been: with colon cancer deaths unchanged, screening and pre-malignant treatments are ever more important.

I think that would be editorialized.

What would be more accurate is to say the title is incomplete. Te details matter.

If the claim was "Voluntary colonoscopy screening does not reduce the risk of death over a 10 year period" it would likely be more accurate and at least calls out the "voluntary" nature of the patients examines and the limited time span of the analysis.

No study is ever perfect and everyone has limitations. You usually learn more by investigating the limitations than poking holes in the conclusions.

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#104

Post by pessimizer »

divbzero wrote: post #22
pbourke wrote: post #15

Earlier quoted context omitted.

In this case they are examining colon cancer and deaths from it, and the colonoscopy is a diagnostic test for colon cancer. I feel that the results are being presented to the public in a very misleading way. People will read this headline and conclude that they don’t need to get a colonoscopy which I don’t think follows from this study at all.

I agree. Even if intention-to-treat is the gold standard endpoint for trials, a more accurate and nuanced headline for the general public would be: Inviting patients to undergo screening colonoscopy fails to reduce rate of cancer deaths

Or: If you compare a group of people who never get colonoscopies with a group of people containing many who do get colonoscopies, the same number of people die.

Imagine two cages filled with identical mice. One you drop some food into, and the other you don't. They starve to death at the same rate. Surprised?

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#105

Post by lupire »

bitcurious wrote: post #96
JohnJamesRambo wrote: post #90

Earlier quoted context omitted.

I’m so confused though, because based on my reading of it, it seems like the prostate screening thing where yes it might find cancer but no it won’t prevent deaths, so it might be better to just not know/do invasive procedures and treatment for it. Is that the wrong conclusion to reach from the data?

You could think of screening as a bet on anti-cancer drugs getting better over the next N years.

Or you could wait for better drugs before getting an invasive screening.

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#106

Post by greedo »

prirun wrote: post #98
em500 wrote: post #49

Earlier quoted context omitted.

The problem with the title is that it might lead individuals to believe they shouldn't bother with getting a colonoscopy. You can't conclude that from this study at all. If your doctor recommends you to get one, you probably should. The study answers a question pertaining public health policy (should we invite everyone in some age group for a colonoscopy?). It does not answer any individual health/treatment/screening…

> The problem with the title is that it might lead individuals to believe they shouldn't bother with getting a colonoscopy. You can't conclude that from this study at all. If your doctor recommends you to get one, you probably should. The problem with your doctor's recommendation is that doctors recommend colonoscopy based on age, not whether you have any factors that might indicate colon cancer. I have no cancer of…

No one in my family history going back several generations had colo/rectal cancer. Yet I developed it at age 41. Diet is increasingly viewed as a factor.

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#107

Post by PaulHoule »

bitcurious wrote: post #96
JohnJamesRambo wrote: post #90

Earlier quoted context omitted.

I’m so confused though, because based on my reading of it, it seems like the prostate screening thing where yes it might find cancer but no it won’t prevent deaths, so it might be better to just not know/do invasive procedures and treatment for it. Is that the wrong conclusion to reach from the data?

You could think of screening as a bet on anti-cancer drugs getting better over the next N years.

Prostate cancer is different from colon cancer.

In the case of colon cancer detected in a colonoscopy they can snip it out right there without a lot of effort, risk or lost function. Surgery on the prostate is likely to cause all sorts of problems for men.

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#108

Post by gregw2 »

seanmcdirmid wrote: post #77
ricardobeat wrote: post #43

Earlier quoted context omitted.

You have to look at it from the perspective of medical practice. The hypothesis is that inviting people for a regular check up reduces mortality. If a lot of people don’t take up the offer because the procedure is too invasive, carries some risk, etc. then that is a very relevant variable to take into account. Vs, for example, fecal testing as mentioned in the article. It could have a lower precision, but if uptake i…

American health insurance really screws the pooch here. If you go for a colonoscopy without a previous fecal testing, it is a diagnostic procedure that is fully covered by your insurance without triggering deductible and copay. However, if you go for fecal testing first and then they find something suspicious that warrants a colonoscopy, it is no linger considered diagnostic (you have a legitimate problem now) and de…

You are complaining about the rare situation where someone gets fecal scanning first (and I agree this leads to perverse incentives)... But here's what the real racket is... American healthcare considers the colonoscopy preventative so the exam is covered... but if they see even a single polyp and decide to cut it off to get checked whether it is benign or not, that is not preventative but is diagnostic and thus is not covered and costs you $$$ in copays.

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#109

Post by donohoe »

I personally advise everyone to get a colonoscopy.

I personally know 4 people who had the procedure and cancer was detected. Some further along than others. All still living.

Colonoscopy is one of the few procedures that as they screen they can also take action.

Re: Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

#110

Post by Clent »

prirun wrote: post #98
em500 wrote: post #49

Earlier quoted context omitted.

The problem with the title is that it might lead individuals to believe they shouldn't bother with getting a colonoscopy. You can't conclude that from this study at all. If your doctor recommends you to get one, you probably should. The study answers a question pertaining public health policy (should we invite everyone in some age group for a colonoscopy?). It does not answer any individual health/treatment/screening…

> The problem with the title is that it might lead individuals to believe they shouldn't bother with getting a colonoscopy. You can't conclude that from this study at all. If your doctor recommends you to get one, you probably should. The problem with your doctor's recommendation is that doctors recommend colonoscopy based on age, not whether you have any factors that might indicate colon cancer. I have no cancer of…

The study does not say that coloscopies don't help. The study measures a difference in the study's population. The study does indicate they don't affect outcomes as much as expected. However, their affect is positive.

The study's measured affect has wide errors bars indicating a larger sample size is needed. Subsequent studies could show the affect is more inline with expectations but are unlikely to show less affect.

The question as to whether this will be used to reinforce hesitancy for this procedure; we can already see it in the comment. Logic and reason are not naturally occurring traits. I predict this will be used to move more people into the control group. Going against medical advice is anecdotally meaningful.

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