Colorectal cancer statistics in Japan: data from JSCCR registration, 1974-1993.

Japanese colorectal cancer statistics from 1974 to 1993 are reported, based on the accumulated data registered by the member institutions of the Japan Society for Cancer of the Colon and Rectum (JSCCR). Both colon and rectal cancers were more prevalent in men than in women. In both sexes, colonic cancers were more prevalent than rectal cancers, and a greater increasing trend was seen in colonic cancers. Moderately differentiated adenocarcinoma seemed to have increased in recent years. The resectability and operative death rates improved slightly, but the ratio of stage I + II/III + IV cancers (both colonic and rectal) did not change at all during the 20-year period reported. The yearly improved survival in both colonic and rectal cancers, particularly in stages II and III, may well reflect improved surgical techniques.