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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

#131

Post by hef19898 »

PaulHoule wrote: post #107
bitcurious wrote: post #96

Earlier quoted context omitted.

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.

And not having surgery for it can mean death. Steve Jobs, even it wasn't prostate cancer, should serve as good example of how not to tackle it. Or at least to show what not tackeling it looks like, because feel free to do what you want, but be aware of the consequences.

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

#132

Post by hef19898 »

ChrisMarshallNY wrote: post #120
jrochkind1 wrote: post #99

Earlier quoted context omitted.

I guess the question is if the scan makes a difference in intensity of treatment, if people who got a colonoscopy had fewer surgeries or fewer/less radiation. It doesn't say, I think? It's not at all obvious it would. (In general, one would think people who got the colonoscopy got more treatment -- in this case despite having no lower a death rate -- but perhaps it does not include as much intense treatment).

In my friend's case, it was Stage IV, before it was found. That may have had something to do with him not getting a gerbillcam until he started having symptoms. I will say his treatment wasn't fun, at all, although he'll be OK, in the long run (but chemo never leaves you the same).

IMHO it is chemo and the fact you very seriously face the prospect of an ugly, and lengthy, death that changes you. You and your loved ones, it affects everyone, I know it does.

Good for your friend to be on the way of recovering!

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

#133

Post by tssva »

A lot of the comments here seem to come from the perspective that a colonoscopy is the only way to screen for colorectal cancer. There are also fecal sample tests such as FIT and FIT-DNA. Both involve home collection of fecal samples for testing. In the case of FIT yearly and FIT-DNA every 3 years. In the case of both if there is a positive result a colonoscopy is then performed. Outside the US annual FIT testing seems to be the standard of care versus a screening colonoscopy. A similar study with yearly FIT tests would be interesting to see. I suspect you might have a better compliance rate than the 42% seen in this study.

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

#134

Post by ljf »

donohoe wrote: post #109

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.

This. My father had a faecal test which showed he possibly had cancer - the colonoscopy confirmed this.

Sadly my oldest brother didn't catch his so quickly and the colonoscopy he had showed he was pretty far along, and ultimately the cancer spread and killed him.

I now have one every 5 years until I hit 50 then I'll move to every 2 years. The test is pretty pain and issue free, the only 'bad' part if the laxatives first, but after seeing my brother die, it is well worth the couple of hours of discomfort.

My older brothers had continued with faecal testing, but after some pushing moved to colonoscopies too, as we'd rather catch it early, than once it has taken hold.

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

#135

Post by 2devnull »

timr wrote: post #128
phkahler wrote: post #124

Earlier quoted context omitted.

I'm also confused about the "invited" group. Not all of them had the procedure and there is a part talking about lower cancer rates among the subset that actually accepted the invite. It sounds like there is still confusion about how to interpret it.

There's not confusion. The study did an intention-to-treat analysis, which failed to find a significant result. "Intention to treat" here means that you count everyone in the group that got an invitation to get a colonoscopy, regardless of whether or not they actually did it. Though this sounds counterintuitive, it's the "gold standard" because, if you don't do this, you leave yourself open to bias -- maybe the peopl…

The important part of your post, “If that’s true…”

Is it true, or not?

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

#136

Post by vharuck »

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 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.

This study is meant to inform the public health policy of asymptomatic screening. They tried to see if there was a benefit in offering screenings to random patients, regardless of medical history. The currently recommended screenings for asymptomatic people were adopted because meta-analyses showed they reduced cancer mortality. In the US, the US Preventive Services Task Force keeps up with new studies and revises their recommendations: https://uspreventiveservicestaskforce.org/uspstf/home.

For people with family history or other risk factors, doctors will follow different screening guidelines or just order tests whenever they think it useful.

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

#137

Post by droopyEyelids »

donohoe wrote: post #109

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.

Your comment is an example of the statistical/scientific misunderstandings that lead to 'overdiagnosis' https://www.cancer.gov/publications/dictionaries/cancer-term...

Not all cancer is the same.

Every person will have some amount of cancer as they get older. Some of the cancer will not be aggressive or disruptive enough to cause a problem before the person dies of another old-age related infirmary.

Treating cancer is not free. Treatment reduces the quality of life of the person treated. Elderly people are slower to heal, and more at risk for complications. To treat a cancer that would not cause problems in the natural lifespan of its host is an expensive mistake.

Screening technology can expand our ability to detect cancer without giving us the insight to know dangerous cancer from inconsequential cancer. When we go on to treat inconsequential cancer we've actually reduced the years of healthy life of the patient.

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

#138

Post by timr »

2devnull wrote: post #135
timr wrote: post #128

Earlier quoted context omitted.

There's not confusion. The study did an intention-to-treat analysis, which failed to find a significant result. "Intention to treat" here means that you count everyone in the group that got an invitation to get a colonoscopy, regardless of whether or not they actually did it. Though this sounds counterintuitive, it's the "gold standard" because, if you don't do this, you leave yourself open to bias -- maybe the peopl…

The important part of your post, “If that’s true…” Is it true, or not?

To the extent that we can assess it by this single study, yes.

There is no answer to the question you're asking. You're seeking absolute certainty where none can be had. We only know what we know as far as we know it. Always and everywhere.

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

#139

Post by dahart »

timr wrote: post #128
phkahler wrote: post #124

Earlier quoted context omitted.

I'm also confused about the "invited" group. Not all of them had the procedure and there is a part talking about lower cancer rates among the subset that actually accepted the invite. It sounds like there is still confusion about how to interpret it.

There's not confusion. The study did an intention-to-treat analysis, which failed to find a significant result. "Intention to treat" here means that you count everyone in the group that got an invitation to get a colonoscopy, regardless of whether or not they actually did it. Though this sounds counterintuitive, it's the "gold standard" because, if you don't do this, you leave yourself open to bias -- maybe the peopl…

> Though this sounds counterintuitive, it’s the “gold standard” because, if you don’t do this, you leave yourself open to bias

Isn’t there just as much chance for bias if the treatment is voluntary? Maybe the people who are more likely to have health issues are less likely to treat them.

I think there is a valid question about how effective a colonoscopy is given that you get one, and a separate valid question about how effective telling people to get colonoscopies is. According to the article, this paper answer the second question strongly via “gold standard”, and the first question less strongly via secondary analysis.

Part of the reason it’s counterintuitive here is the title of the article is “effect of colonoscopy screening”, not “effect of a doctor’s invitation to have a colonoscopy screening”. The title more than suggests that we’re comparing the outcomes of actually having the screening to not having one.

> maybe the people who don’t have the time/inclination to do one would be better served by an alternative test.

I see what you’re saying - the overall effectiveness of our current system may be low because of a low rate of voluntary adoption of the colonoscopy is low, and even a lower accuracy screen could be more effective if more people opt in.

One problem with drawing a conclusion this way is it ignores the possibility for dramatic changes in either opinion or in procedure of colonoscopies. What if we had the tech to do the colonoscopy at home in private? Would that change the voluntary rate of testing dramatically?

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

#140

Post by naasking »

Good discussion here, but I think the main message might get lost in the noise:

* Colonoscopies reduce incidence of colon cancer but apparently not death from colon cancer.

* This is probably because colon cancer therapies are good, so even if you get colon cancer your prognosis is good.

* The take-away is not that colonoscopies reduce your chances of death, but that they reduce your chances of having to suffer colon cancer and subsequent therapies. That might still be a good trade-off.

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