Fecal occult blood screening--trial evidence, practice and beyond

Colorectal cancer is a leading cause of morbidity and mortality in Western countries. Primary prevention and early detection of this malignancy has been shown in multiple research set-ups, and using different modalities, to be effective in reducing the incidence and mortality rates of this disease. Three randomized controlled trials have been conducted over the last 30 years to evaluate the efficacy of periodic screening with fecal occult blood tests (FOBT). These studies have consistently demonstrated mortality reduction with biennial as well as annual testing after 8-18 years of follow-up. A significant primary prevention effect through reduction of colorectal cancer incidence was also reported. The results of the Israeli population-based screening program using Hemoccult Sensa show that it is possible to achieve a high detection rate in a well-organized community set-up and, in addition, also a shift in tumor stage towards smaller tumors, a low positivity rate, and an acceptable false positivity rate. FOBT is cheap and performs very well in cost effectiveness analyses evaluating the cost of detecting one cancer. This is quite a rare situation where mortality reduction can be achieved with a simple rather than a sophisticated technology. Research to further enhance the cancer detection capabilities of FOBT through the incorporation of molecular testing of the stool for tumor genes is underway. Multiple policymakers are already recommending this procedure for routine screening of average risk population. Taking their recommendations into action is of major importance.