A mass screening program for colorectal cancer using chemical testing for occult blood in the stool.

Following five promotional and educational programs on CBS-TV news in Chicago, 54,101 Hemoccult kits were requested by the public and distributed by seven cancer detection facilities. Only 14,074 individuals completed the test. Six hundred and seventeen or 4.38% were positive. Two hundred and fifteen test positive persons failed to respond to repeated notification. In 123 positives, diagnostic tests by the private physician were considered incomplete. In 33 positives, the private physician did no further testing at all. In 152 positives, no abnormality could be found, but work-up was variable. One hundred and eighty-seven had abnormalities other than cancer, including 40 with polyps. Twenty-seven asymptomatic and two symptomatic cancers were found. Nearly two-thirds had Dukes A or B lesions, while one-third had Dukes C tumors. Public compliance in both completing kits and following through with positive results was low. Physician evaluation of positives was often incomplete. Chemical testing for occult fecal blood, when properly combined with other tests such as proctoscopy, has the potential for lowering mortality from colorectal cancer. Continued public and professional education is needed.