The risk of colorectal cancer was significantly increased among people who had undergone obesity surgery in a retrospective cohort study of more than 77,000 obese patients enrolled in a Swedish registry.The increased risk for colorectal cancer was associated with all three bariatric procedures – vertical banded gastroplasty, adjustable gastric banding, and Roux-en-Y gastric bypass – and increased further over time, reported Dr. Maryam Derogar, of the Karolinska Institutet, Stockholm, and her associates. No such pattern over time was seen among the obese patients who did not have surgery.
“Our data suggest that increased colorectal cancer risk may be a long-term consequence of such surgery,” they concluded. If the association is confirmed, they added, “it should stimulate research addressing colonoscopic evaluation of the incidence of colorectal adenomatous polyps after obesity surgery with a view to defining an optimum colonoscopy surveillance strategy for the increasing number of patients who undergo obesity surgery. The study was published online in the Annals of Surgery