Frequency of colonoscopy after removal of cancerous polyp
Dear OncoLink "Ask The Experts,"
I'm 54 years old and last October I had a routine colonoscopy and they found a medium size polyp and removed it. I was told the top part of the polyp contained cancer cells but not the stem so to be on the safe side my doctor recommended I have a sigmoid colon resection. Everything came out clean. I was told to get another screening in 3 years but would feel better if I got one every year instead. Is there any disadvantage to having this done yearly to be on the safe side? I have no history of colon cancer in my family.
Timothy C. Hoops, MD, Clinical Assistant Professor of Medicine in the Gastroenterology Division at the University of Pennsylvania and Director of Gastroenterology at Penn Medicine at Radnor, responds:
Your situation occurs with some frequency and you have a very good question. First, I am glad they were able to get all the cancer out. In general, you might consider your polyp an advanced polyp. A study published in 1993 demonstrated that with advanced polyps, a colonoscopy performed at 3 years was as effective as one done at 1 year. This important study changed the way GI was practiced. You have had a polyp that was removed. Although it had cancer, it appears to have remained very local. The concern is not whether this polyp will recur; they generally do not. (And the region your polyp was located has been removed, in any case.) Rather, the follow-up procedures are done to look for new polyps. In most cases, the process of moving from normal to polyp to cancer is a 10 to 15 year process or longer. There are a few instances where things can progress more quickly, but it is unlikely. I understand the concern and desire for more frequent studies, but I think you would be very safe waiting for 3 years. Colonoscopies are very safe but they do have some risk associated with them. The last thing one wants is a complication from a procedure that really wasn't necessary in the first place. My recommendation for individuals in this circumstance to get a repeat colonoscopy at three years.