[Mass screening for colorectal cancer].

Considering the present state of knowledge, only the strategy of screening for intestinal tumours at the asymptomatic stage could reduce such a problem as colorectal cancer. Data from case-control studies provide evidence of the efficacy of screening by rigid proctosigmoidoscopy. But compliance with such a strategy is not known. The effectiveness of screening by sigmoidoscopy has yet to be demonstrated. A European controlled study of flexible sigmoidoscopy in association with the Hemoccult test versus the Hemoccult test alone has been set up. Evaluation by a randomized screening trial with a single flexible sigmoidoscopic examination at age 55 to 60 years has also been suggested. Case-control studies and a randomized study conducted among volunteers demonstrate that it is possible to reduce mortality from colorectal cancer in people who accept screening with faecal occult blood testing, using the Hemocult test. Four population-based studies have been set up in Europe (in England, Denmark, France and Sweden). They are based on a biannual Hemoccult test. Compliance in the test group ranges between 55% and 65% in the first screening campaign and remains high in the following screening campaigns. In France, to achieve this goal, the test must be proposed by GPs and then mailed to those who do not consult GPs. Reliable mortality data will be available within 1 to 3 years. The results of the European trials must be awaited to know if screening biennually is effective in reducing colorectal cancer mortality.