Screening for Colorectal Cancer—Which Strategy is the Best?

Extract

Screening for colorectal cancer (CRC) can decrease the risk of death from CRC. In addition, detection and removal of precancerous lesions can reduce the incidence of CRC itself. Initially, randomized trials assessed the efficacy of screening using fecal occult blood testing (FOBT) and found modest reductions in mortality ( 1–4 ), but not in incidence ( 5 ). Nonetheless, these trials were followed by widespread recommendations for screening in the United States by professional societies and the American Cancer Society, using FOBT, flexible sigmoidoscopy, and colonoscopy ( 6 ). Over time, those recommendations have been refined but continue to include these tests ( 7 ). Other countries took a more cautious approach and implemented screening programs using FOBT, but decided to wait for more substantial evidence about other screening methods.

Recently, Atkin et al. ( 8 ) reported that a randomized trial of one-time flexible sigmoidoscopy conducted in the United Kingdom demonstrated statistically significant reductions in both CRC mortality and incidence over a median follow-up of 11 years. In this issue of the Journal, the results of the Screening for COlon REctum (SCORE) trial reported by Segnan et al. ( 9 ) happily confirm those of the UK trial ( 8 ). This randomized trial was conducted in Italy and compared the effect of screening with flexible sigmoidoscopy (vs usual care) on CRC incidence and mortality among men and women, aged 55–64 years, randomly selected from six trial centers. Flexible sigmoidoscopy was performed on 9911 subjects in the flexible sigmoidoscopy (or intervention) group. The CRC incidence rate in the intervention group was statistically significantly reduced by 18%, and the mortality rate was non-statistically significantly reduced by 22% compared with the rates in the usual care group. The two studies ( 8 , 9 ) used subjects in the same age range and the screening methods in the SCORE trial were very similar to those in the UK trial. Now, we can confidently assert that a single flexible sigmoidoscopy examination is an effective method of screening for CRC.