Mass screening for colorectal cancer in Japan.

A mass screening program for colorectal cancer has been conducted in Japan for several years, and the nationwide statistics showed a total of 416,382 participants in 1988. This paper describes the present status of mass screening program for colorectal cancer in Japan and related issues as follows: annual trend of the number of examinees, age distribution of examinees, screening methods, diagnostic methods, evaluation of screening accuracy for fecal occult blood tests, and screening interval.