FAMILY HISTORY OF COLONIC-CARCINOMA AND ITS BEARING ON SCREENING PROGRAMS - A SWISS EXAMPLE

Primary prevention of colorectal carcinoma aims at interruption of the adenoma-carcinoma sequence. Colonoscopy is the most reliable screenin g method, but up to now has only been recommended for persons at high risk. The ongoing 10-year study defines a possible risk group and dete rmines the efficacy of a preventive screening program based on family history. This paper reports on the descriptive statistics of the first five years. All patients with colonic carcinoma diagnosed between 198 7 and 1991 living in the upper part of Canton Basel-Land were register ed. According to the family history, patients with at least one first degree relative with colonic carcinoma were defined as index patients. Their first degree relatives entered a prospective screening program which includes colonoscopy. 230 colonic carcinomas were diagnosed in t he upper part of Basel-Land, representing an incidence of 48/ year/100 ,000 persons. They included 3 (1.3%) hereditary and 227 (98.7%) sporad ic carcinomas. 23 (10%) patients had a positive family history. These patients defined 94 relatives at risk. The incidence of colonic carcin oma in the Canton studied does not differ from that reported in Switze rland. Therefore, this part of Basel-Land can be considered representa tive. The 1.3% hereditary carcinomas are in contrast to the published data of 6%.