A prospective population-based study recorded family trees of 77 colorectal
cancer patients younger than 50 years of age. Using mathematical modeling
of population age-incidence data, we estimate that 1 (95% confidence limits
0 and 3) of these families is expected to meet the Amsterdam criteria I fo
r HNPCC due to chance clustering of colorectal cancer. (C) 2001 Cancer Rese
arch Campaign.