Colorectal cancer screening by fecal occult blood testing: results of a population-based experience

The study evaluated the results of an experimental screening protocol for colorectal cancer by fecal occult blood testing in a municipality of the Province of Florence.

A total of 15,235 subjects aged 50-70 years were invited to perform a 1-day immunochemical fecal occult blood testing without any dietary restrictions. All eligible subjects were sent a personal invitation letter, followed by a postal reminder to non-responders. Subjects with a negative stool test were advised to repeat screening after 2 years. Subjects with a positive screening test were invited to undergo full colonoscopy or a combination of left colonoscopy and a double contrast barium enema.

A total of 6,418 subjects performed the screening test, with an overall compliance of 42.1%. A total of 268 compliers had positive test results. The positivity rate was 4.2%. Detection rate for cancer and for adenomas was 5.1% and 11.6%, respectively. The positive predictive value was 14.3% for cancer and 32.5% for adenoma. A higher compliance was recorded in subjects born in the province of Florence or living in the centre of the town, in married subjects, and in women. The best results in compliance were associated with the direct distribution of fecal occult blood testing kits by general practitioners to their outpatients.

The study provides useful information about the efficiency and feasibility of a screening program for colorectal cancer using fecal occult blood testing. Compliance results confirm the importance of GP involvement in oncological screening.