Distribution of large-bowel cancers detected by occult blood test in asymptomatic patients

Abstract

A randomized, controlled study on occult blood in stool was conducted in 48,000 asymptomatic participants, ages 50-80 yr. Those with positive hemoccult test results underwent a complete colonic workup including colonoscopy and, in some cases, an air-contrast Ba enema examination when total colonoscopy could not be accomplished. From Apr. 1976-Dec. 1980, 113 patients (62 men and 51 women), with an average age of 66 yr, had invasive carcinomas of the large bowel: right colon-25%, transverse colon (included both flexures)-9%, descending colon-10%, sigmoid and rectosigmoid-42%, rectum-12% and anal canal-2%. The stages of the cancers were: Dukes'' A-57%, Dukes'' B-21%, Dukes'' C-19% and Dukes'' D-3%. A complete colonic workup is apparently required for the detection and diagnosis of large bowel cancers in asymptomatic patients.