[Periodic colonoscopic examinations of persons with a positive family history for colorectal cancer. Work Group 'Hereditary non-polyposis- colon-rectum cancers'].

Individuals with one first-degree relative with colorectal cancer diagnosed before age 45 years and those with two first-degree relatives with colorectal cancer run a significantly increased risk (relative risk: 4-6) of developing colorectal cancer. Based on calculation of the mortality due to colorectal cancer for the age group 50-70 years (which is higher than the mortality due to breast cancer) surveillance may be justified, e.g. by colonoscopy at 5-year intervals from the age of 45-50. The total number of people in the Netherlands in this high risk group is estimated at 10,000. The authors conclude that prospective studies are needed to assess the cost-effectiveness of such a programme.