@ams5796 It’s just fact… BTW lynch runs in by family and for women it can be hidden ovarian cancer so getting a hysterectomy is key to cure it. Both sexes can get cancerous polyps. My family has a history of polyps. If anyone on this thread has a history of colon polyps of any kind then get genetic tests for Lynch disease like now.
BTW - since I am on this thread. I am scheduling my colonoscooy for next month.
Some people are at higher risk than others. While a person who is considered at low risk can still develop cancer, relative risk is a factor to consider in evaluating risk vs. benefit of various screening protocols. Most people do not have polyps, and most polyps will not become cancerous — so while it is definitely true that a colonoscopy is the only way to remove polyps — that is not a factor that impacts the vast majority of people undergoing routine screening colonoscopies.
The article written by the gastroenterologist which was cited above refers to a study published in the New England Journal of Medicine. Here is a summary of the stats from the article itself – which also answers the question about detection of polyps.
Link: https://www.nejm.org/doi/full/10.1056/nejmoa1311194
The study was done by having all participants do all 3 screening procedures.
For purpose of argument I will round up the number of participants with polyps or cancer to 8.5%. Obviously, those individuals are better off with colonoscopy.
But the risk/benefit analysis has to also look at the 91.5% who did not have cancer or pre-cancerous polyps*. For all of those people, in hindsight, the colonoscopy was unnecessary. It tested for something that they turned out not to have. Or, in other words, they would have been just fine with no testing whatsoever.
(The tables included with the article are more informative as to numbers. There was a larger number of participants who had smaller polyps (“nonadvanced adenoma”) – and usually those do not become cancerous – but even accounting for those, 62.8% of the group had purely negative results. A different study has shown that only about 1% of people with nonadvanced adenoma later develop CRC - https://www.healio.com/gastroenterology/interventional-endoscopy/news/online/%7Bd2802ff0-4923-4b86-84d7-f6e5a83970af%7D/colon-cancer-risk-depends-on-polyp-type-found-during-colonoscopy )
Obviously the whole point of screening is that we can’t know whether or not the test is needed until after it is done. We don’t know which person falls into the 8.5% group who benefits from colonoscopy, or the 91.5% who are going to have negative results no matter what form of screening is used.
But that is a factor that can be considered when doing an overall risk/benefit analysis. So contrary to the GI’s opinion about “science” over “convenience” ---- this reported data is science, and “inconvenience” is something that matters, a lot, to people who undergo screening that, with the benefit of hindsight, they may not really have needed.
So on an individual level – I agree that the choice should be made by the patient, based on consideration of whatever factors are important to them.
But the point is that even though the FIT was much less effective in detecting cancers or polyps among the minority of patients who had positive results from their colonoscopy – across the group as a whole the difference becomes less significant. Plus the other factor is frequency of screening – even though FIT is significantly less effective at detecting polyps, some of that is countered by the benefit of annual screening as compared to screening at 10 year intervals.
The GI who wrote the article extrapolated, "Cologuard could fail to detect colorectal cancer in 1 out of every 13 people who use the test " – but that’s missing the point that only a very small percentage of people screened have cancer or precancerous polyps. So the actual number of cancers/precancers that might be missed with the Cologuard test is probably more along the lines of 1 out of 150.
I don’t think it makes sense to compare the choices being made by individuals with a known family history of a predisposing condition to people with no risk factors. It’s not a matter of whether the tests are the same – it’s a matter of which type of screening is most appropriate for different individuals, based on their own determination and needs.
And we can argue semantics all day, but the CDC lists the various stool tests as being screening tests. So it is not true at all to claim that a given test is not “screening” because it is somewhat less sensitive than another test. That is confusing the term “screen” with “diagnosis.” The stool tests are screens, but they cannot provide diagnosis – whereas a colonoscopy can be used both as an initial screen, or as a diagnostic tool following a positive result on a screening test.
“I would also want to know how effective the FIT tests are at finding precancerous polyps”
I had a small precancerous polyp removed 8 1/2 years ago. I occasionally wonder what it would be by now if it had not been removed. I am quite glad that it is gone.
@calmom. All your points are well taken. But the problem is not everybody really knows their family history. Depending on your age alot of things were either not discussed or known back then. Lynch has been running in my family since my mother had ovarian cancer at a young age, both her sisters had cancerous polyps… At a young age, cousins had similar things but it was only found to be Lynch in the last few years since genetic testing became more available and affordable. My son had a form of eplispsy when he was young and since grew out of it. . We asked around since no one in my family had it. We later found out that one of my first cousins son had it but never wanted people to know or talk about it. I hear things like this all the time. But you are correct , if not family history that you know about, your chances are slimmer to develop at problem. But yes, if a known family condition then follow through with your doctors advice.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5833039/ compares cancer screening recommendations across various rich countries.
For colon cancer (table 4), almost all countries recommend stool tests (usually FIT, although sometimes gFOBT, which is less convenient due to dietary limitations and has more false positives) as the primary screening method. The three exceptions are the US, Germany, and Austria. The latter two recommend both yearly FIT and colonoscopy every 10 years.
Having worked in a colonoscopy center, I have a different perspective than many. The vast majority of people at my center, especially those 50 and older, had polyps found in their first screening colonoscopy. That could be because more of those patients than the general population identified some kind of risk factor that drove them to follow the colonoscopy screening guidelines. The vast minority of those were actually “obvious to the naked eye” cancerous polyps. Many were identified as pre-cancerous, but still, most polyps turned out to be benign. They still need to be removed, because benign polyps can nevertheless grow to be very large and thus cause problems for the affected patient.
Everything is risk/benefit of course. My DH had no known relatives with colon/rectal cancer. He was diagnosed at age 46 with stage 3 cancer after noticing blood in his stool. His tumor was one of those that was easily identifiable to be cancer by the GI doc immediately upon visualization during his colonoscopy. Because he needed aggressive IV chemo after his surgery to remove part of his colon, he had to have a temporary ostomy for 8 months. Let’s just say that it was no walk in the park for a young go-getter businessman to have to manage that situation. Thank God it was only temporary.
I also have no family history of colon cancer, yet my first polyp, though benign, was incredibly large, so it’s good I went in when I did. I did drag my feet quite a bit on the follow up, since I knew the first one had been benign. I’m not likely to do that again, since there’s no guarantee I won’t develop another large polyp in the future. Also, I need to set a good example for my daughters, since they ARE considered to be at risk with one parent having had early colon/rectal cancer.
There won’t be any more throwing the dice in this family.
I will feel much more comfortable with the stool testing when they can make it sensitive enough to find polyps before they get to the bleeding/DNA shedding stage so that the chance of having to have a colon surgery is completely eliminated.
If you consider yourself high risk, then you may want to do both colonoscopy at whatever year intervals and FIT every year other than scheduled colonoscopy years.
^^^There is certainly nothing to lose by doing that, and much to gain.
Keep in mind that colonoscopy is far from 100% effective at finding cancer or polyps.
See “The Miss Rate for Colorectal Adenoma Determined by Quality-Adjusted, Back-to-Back Colonoscopies” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3286741/ (“The miss rates of polyps, adenomas, and advanced adenomas were 16.8%, 17%, and 5.4%, respectively. The smaller polyps and increased number of polyps detected during the first colonoscopy were more likely to be missed”)
“Diagnostic miss rate for colorectal cancer: an audit” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4290010/ (“However, 8% (12/150) patients had a normal investigation in the 3 years preceding diagnosis of CRC. … Seven of these 12 patients had advanced disease, 2 with stage III disease and 5 with stage IV disease.”)
“Miss rate of colorectal neoplastic polyps and risk factors for missed polyps in consecutive colonoscopies” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5478767/ – (“In this quality-adjusted, consecutive colonoscopy study, we found that the miss rate for adenomas was 24.1% and that for advanced adenomas was 1.2%… Several previous studies reported that the miss rates for total polyps, adenomas, and advanced adenomas were 16.8% to 28%, 16% to 26%, and 1.7% to 11%, respectively”)
I find this to be concerning in the context of the recommended 10 year interval between testing. I also think the miss rate for polyps is probably slightly higher, because the studies were done by having test subjects undergo two successive same-day colonoscopies and comparing results – but it is still possible that some patients had small polyps that weren’t detected with either colonoscopy. (In fact, in my mind more likely that a polyp that is missed in one colonoscopy at the same facility would be missed a second time, than found).
But my point isn’t tied to specific stats – it is tied to the fact that there will be a non-trivial number of patients given the all-clear after a 1st colonoscopy who may have undetected polyps that become cancerous within a time frame of well under 10 years.
Part of the reason for the recommended 10 year interval is due to the cost & invasiveness of the colonoscopy process – it is a determination that the detriment from too many colonoscopies outweighs the risk of some patient who have undetected and relatively fast grown polyps. See “Know the guidelines: How often do you need to repeat a negative colonoscopy?” at http://retroflexions.com/endoscopy/know-the-guidelines-how-often-do-you-need-to-repeat-a-negative-colonoscopy/ for a discussion of this problem. Basically, odds are that the person who has had the clear first time screen is statistically unlikely to develop cancer within the 10 year interval… but that’s not much consolation for the small percentage of patients who do develop what the medical professionals refer to as “interval” cancer.
I don’t understand why patients are not advised to do both – a colonoscopy once every 10 years, with annual FIT testing in between. I realize that there will be some FIT false positives that will result in unnecessary repeat colonoscopies … but does that risk outweigh the known risk that a small fraction of colonoscopy patients will develop interval cancers that could potentially be caught?
I just had a Cologard. The Cologard, as mentioned before, does test for blood but its main purpose is to test for DNA indicative of cancer. I have a lot of sensitivities and would have trouble drinking the stuff that empties us out, and also had serious low blood sugar when I did the prep for a sigmoidoscopy. I just feel too fragile for the colonoscopy and was grateful for this new test.
I read the article linked on this thread and still feel this was better than not doing anything at all.
Or maybe a FIT every other year in a person who had no polyps upon first colonoscopy.
At dr today for 1 year followup on FIT test and he suggested Cologuard instead. My insurance is with Aetna and they will cover it now, which is what I wanted to mention. Gaining acceptance I guess and maybe other insurers have also uodated their policy. They will cover it every 3 years.
https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/colorectal-cancer-screening2 (table at the bottom) indicates that FIT-DNA (Cologuard) every 3 years is slightly less effective at life years gained and colorectal cancer deaths prevented than FIT every year. Followup colonoscopies and their harms from complications are also slightly lower with FIT-DNA every 3 years.
However, FIT-DNA is significantly more expensive than FIT, even accounting for the screening frequency difference.
Yes on the higher cost, FIT was free with my $50 office visit co-pay. Cologuard is around $650, but supposedly Aetna is covering it. If you go to the cologuardtest website, you can see a list of all insurers who will cover it.
I’m on Medicare now and I know that both FIT and Cologuard would be covered… but I’m leaning on sticking with FIT based on data such as the what @usbalumnus referred to. I think the key benefit is the yearly screening vs. 3-year intervals. Cologuardseems to be more effective than FIT if done annually. I don’t know if it is possible to combine them – (Cologuard once every 3 years, with FIT during the intervening 2 years) – though FIT Is cheap enough that a patient who wants it could pay out of pocket if not covered.
I found another chart with a good illustration of the comparative data here: https://www.cdphp.com/-/media/files/providers/toolkits/colorectal-cancer/colorectal-cancer-screening-with-fit-vs-cologuard.pdf
@calmom It takes about 10-15 years for a small polyp to grow and transform into colon cancer.
Usually. Not always. My friend’s DH had a polyp and 3 years later at follow up had a stage 4 tumor. He died 2.5 years later. Certainly rare, but that’s no comfort to his family.
I personally wouldn’t push it to 15 years. Past history of precancerous polyps and family history matters.
Being a stage 4 rectal cancer survivor I would only use a colonoscopy for colorectal screening. I would advise my loved ones to do the same.
But, I believe I have had this discussion on this thread before. My comment above was in response to someone above who asked why colonoscopies are only done every ten years.
Re: screening intervals
In theory, you could have colonoscopy every year to catch fast growing cancers, or those growing from flat polyps that were missed the last year.
But the added medical risk of complications as well as the added cost of doing so would be significant drawbacks for all but the known highest risk people.
So if you are concerned about being high risk to use colonoscopy every ten years as the primary, you may still want to do FIT every non-colonoscopy year.
My health insurer does a colonoscopy every 10 years, (starting at age 50 but that may have already been moved up), if no polyps are found. During my first colonoscopy I had 3 polyps and they scheduled my next colonoscopy 3 years later. After my second colonoscopy I had no polyps but, since I had fairly recent history of polyps, they scheduled the follow up procedure after 5 years. Again, no polyps and they now wanted me to wait 10 years for my next procedure. After 8 years I started getting a little “antsy” and asked if I could have another colonoscopy before the 10 year wait. They (Kaiser) approved it.