Gastrointestinal Conditions: Colorectal Cancer Screening and Prevention

Colorectal cancer (CRC) is the third leading cause of cancer death in the United States. CRC screening reduces CRC deaths. Although the median age at diagnosis is 67 years, the incidence in younger individuals has been increasing, and younger patients are more likely to present with more advanced disease. In the past, guidelines recommended initiating screening at age 50 years. However, guidelines from multiple organizations now recommend initiating screening at age 45 years. Screening should start even earlier in individuals with genetic risks for CRC. Recommendations about when to discontinue screening vary, but all guidelines recommend continuing at least to age 75 years. After age 75 years, screening should be based on patients' life expectancy, medical status, and values and goals. Colonoscopy is considered the gold standard screening test, but many patients decline colonoscopy because of its invasive nature and associated bowel preparation. Other tests recommended in guidelines include guaiac-based fecal occult blood test, fecal immunochemical and DNA tests, flexible sigmoidoscopy, and computed tomography colonography. Recommended screening intervals vary for each of these tests. Two newer screening tests, not yet included in guidelines, are Epi proColon (methylated septin DNA) assay (which detects methylation of the SEPT9 gene associated with CRC) and capsule colonography. All patients also should be informed about lifestyle and diet-related interventions that can decrease CRC risk.