Importance of Colorectal Cancer Screening

to the editor: I read with great interest the article “Recent Developments in Colorectal Cancer Screening and Prevention,”¹ in American Family Physician. This article hit home on a personal level since my father died of colorectal cancer in 2001. The article¹ provided an excellent literature update that confirmed that screening for colorectal cancer by fecal occult blood testing (FOBT), flexible sigmoidoscopy, double-contrast barium enema, or colonoscopy is cost-effective when compared with no screening. Screening with colonoscopy alone every 10 years, or with the combination of flexible sigmoidoscopy and FOBT, were the most effective strategies in terms of life-years saved.¹

Further work needs to be done to improve the specificity of FOBT while preserving its sensitivity for detecting curable cancers and smaller polyps. Although the findings of one trial² suggest that FOBT can reduce the incidence of colorectal cancer, FOBT has many limitations, including a low sensitivity for polyps, especially the smaller ones. Many screens are false positive, and the test has a low sensitivity for detecting cancers located in the proximal colon. In addition, the topography of colorectal cancer varies by race, which creates racial differences in the utility of such screening tests as flexible sigmoidoscopy and FOBT.³

Furthermore, patients have preferences for colorectal cancer screening techniques that are modestly sensitive to information about test performance and strongly sensitive to the out-of-pocket cost.⁴

The screening and prevention of colorectal cancer will continue to be an important issue for family physicians. It is vital that training programs for family physicians and students stress the importance of screening for colorectal cancer. Colorectal cancer screening should be offered based on national guidelines and on shared decision-making between the patient and the physician.