By the way, doctor: Can I stop getting colonoscopies?
Q. At age 60 I was treated for colon cancer. Since then I've had regular colonoscopies with no further sign of colon cancer. I'm now 84 and healthy. Does it make sense to get another colonoscopy?
A. It's a good question. Discontinuing surveillance colonoscopies in people with a history of colon cancer has never, to the best of my knowledge, been systematically addressed. What would be important to know in making any recommendation would be the precise results of the intervening exams. Since you had cancer, you've probably had five to six colonoscopies. The value of such colonoscopies is the detection and removal of polyps that might eventually lead to cancer. Does "no further sign of colon cancer" mean no polyps in any of those tests? If it does, then I'd probably advise you as I would an octogenarian who hadn't had colon cancer.
Several years ago, researchers from a hospital in Seattle reported data on about 1,200 asymptomatic people who had colonoscopies at their facility. With increasing age, the probability of finding a precancerous polyp went up, and that was especially true for the most worrisome kinds — polyps that are large or have a feathery ("villous") appearance. But the researchers also found that the benefit of the colonoscopies, as measured by the extension of life expectancy, got smaller in older age groups. For people ages 50 to 54, screening colonoscopy added, on average, about 10 months of life. For people ages 75 to 79, the screening added two months, and for those 80 and older, the gain was about a month and a half.