[Comparison of tumor incidence in 251 first-degree relatives of 50 patients with colorectal carcinoma with those of the Basel population].

A tumor-centered family history obtained in 50 patients with colorectal carcinoma without polyposis coli revealed that first-degree relatives of such patients have a 3.6 times greater risk of developing colorectal carcinoma themselves. The simple and harmless family history method can be employed by any physician for the identification of healthy persons at high risk for colorectal carcinoma.