More Evidence That Poor Adenoma Detection Increases Cancer Risk

A screening colonoscopy study performed in Poland (N Engl J Med 2010; 362:1795) and an evaluation of a colonoscopy cohort from Ontario (Gastroenterology 2011; 140:65) have both shown that poor adenoma or polyp detection among doctors leads to more patients developing colorectal cancer. Now, investigators evaluate the association between distal adenoma detection, specifically with flexible sigmoidoscopy, and risk for interval distal cancer using data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer screening trial. This trial recently demonstrated that flexible sigmoidoscopy is associated with a reduced risk for death from distal colorectal cancer and a modest reduction in risk for proximal colorectal cancer (N Engl J Med 2012; 366:2345).

The distal adenoma detection rate during flexible sigmoidoscopy ranged from 2.0% to 7.2% among endoscopists in the lowest quartile of distal adenoma detection rate compared with 11.2% to 15.8% among endoscopists in the highest quartile. Of 66,711 examinations by 93 endoscopists, 32 interval distal cancers were detected. The rate of interval cancer was 9.0 per 10,000 examinations in patients examined by endoscopists in the lowest quartile of distal adenoma detection compared with 3.0 to 5.4 per 10,000 examinations in patients examined by endoscopists in higher quartiles. The risk for interval distal cancer was increased for patients of endoscopists in the lowest quartile versus all other quartiles (odds ratio, 2.4; P=0.02).