Adenoma Detection Rate Pays Off 3x in Cancer Risk Reduction

A large-scale study of patients who underwent colonoscopies shows that adenoma detection rates closely tracked the future risk of colorectal cancer, and that for each 1 percent increase in adenoma detection rate, there was a 3 percent decrease in colorectal cancer risk.

The results of the study, which was conducted by Kaiser Permanente researchers using large banks of electronic medical records data, were published in the New England Journal of Medicine.

The study is the largest ever conducted and the first in the United States to examine the relationship between detecting adenomas and the future risk of colorectal cancers. The colonoscopies studied were performed on Kaiser Permanente patients between Jan. 1, 1998 and Dec. 31, 2010, in northern California. All patients were age 50 or older and had at least six months of follow-up after their colonoscopy. The gastroenterologists were experienced: All had completed at least 300 colonoscopies, and each performed an average of 2,150 colonoscopies per year.

Among the nearly 264,972 colonoscopies studied, 712 patients were subsequently diagnosed with a colorectal cancer after being followed for up to 10 years after their exam; these included 255 advanced-stage cancers and 147 deaths.

We found that higher levels of detection were associated with a decreased subsequent risk of cancer,” c, M.D., a gastroenterologist and Kaiser Permanente research scientist, said in a statement accompanying the study's publication. “Taking out adenomas prevents cancers, and early detection likely prevents many cancers.”