[Screening and prevention of colorectal cancer]

Population-based studies have shown that guaiac faecal occult blood testing followed by colonoscopy in case of positivity can reduce colorectal cancer mortality. However attention has been given for alternative tests in particular to immunochemical faecal occult blood tests. It is now clear from available data that immunochemical tests outperform guaiac tests. They should be preferred for CRC screening. The one sample strategy has been adopted in most screening programmes. Given the superior performance characteristics of immunochemical, it is reasonable to assume that an organized programme using this type of test would lead to a greater reduction in colorectal cancer mortality and possibly of colorectal cancer incidence. Epidemiological studies allow us to define subjects at very high risk (genetic origin) and high risk for colorectal cancer. Colonoscopy screening is recommended in first degree relatives of patients with colorectal cancer or large adenoma diagnosed before 60 years or with two affected first-degree relatives, in subjects with an extended inflammatory bowel disease, or with a personal history of large bowel cancer or large adenoma.