Alan Cassels of British Columbia writes, “The polyp police are coming.”
He explores the introduction of a new Provincial Colon Screening Program in British Columbia. And he raises many questions in a very thoughtful analysis:
“Does a polyp automatically mean a death sentence?
Not at all—only about 2.5 polyps in a thousand will progress to cancer. There is much medical debate around how fast even “precancerous” colonic polyps will go on to develop into full blown cancers; estimates range from 10 to 25 years. Admittedly, finding things that could be precursors to cancer and then leaving them alone is very hard to do. Hunting down and removing polyps seems relatively easy to do and lucrative for those doing it.
But before fully embracing the program, we need to understand the problems colonoscopies themselves can cause both individuals and the health care system.
In the last few years even the most-studied and widely-used screening programs (for breast and prostate cancer, for instance) have faced evidence-based arguments about whether they were doing more harm than good. The main issue has been the possibility of overdiagnosis. In the case of colon cancer, because most of us will have polyps and very few of us will die from them, screening is also liable to result in overdiagnosis and overtreatment.
If and when polyps are found, people may live under a dark cloud, with a “pre-cancerous” label for the rest of their lives. They will certainly be more frequently reminded of their colon health because they will receive many future invitations for follow-up colonoscopies. There is some evidence that depression and suicide is higher among those who submit to screening programs.
From my perspective as a researcher, we need better evaluation of existing screening programs to estimate the benefits; better predictions so we can estimate the burden of the program on the gastronenterology profession; and better information so that people go into screening knowing what to expect—both the potential benefits and potential harm—so they can opt out if they don’t like the odds presented to them. At the end of the day, well-informed citizens, not physicians or the government, should determine if they want to submit to a colon screening program around which there are many questions and unknowns.”
An infographic from the article:
Meantime, this week’s BMJ has a paper, “New polyps, old tricks: controversy about removing benign bowel lesions,” that delivers these key messages:
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