Offering sigmoidoscopy screening to adults reduced colorectal cancer incidence and mortality in men, but had little or no effect in women, researchers reported in the Annals of Internal Medicine.
Investigators randomly assigned 98 678 study participants aged 50 to 64 years who lived in Norway to a single screening with flexible sigmoidoscopy, with or without additional fecal blood testing, or to no screening. Participants with positive screening results were offered colonoscopy. After 17 years of follow-up, colorectal cancer incidence decreased by 34% and mortality declined 37% among men in the sigmoidoscopy group compared with men who weren’t screened. Little or no reduction in colorectal cancer risk or mortality occurred among women screened with sigmoidoscopy compared with those not screened.