Colorectal cancer is the second leading cause of cancer-related deaths for men and women in the United States, with Americans having a 5 percent lifetime risk. The usual development of colorectal cancer is a polyp that slowly increases in size and evolves into cancer. Screening is valuable because early detection and removal of premalignant adenomas or localized cancer can prevent cancer or cancer-related deaths. To determine current standards for screening, the American College of Physicians developed guidelines from the American Cancer Society, the U.S. Multi-Society Task Force on Colorectal Cancer, the American College of Radiology, the Institute for Clinical Systems Improvement, the U.S. Preventive Services Task Force and the American College of Radiology. After assessing this information, the American College of Physicians developed these guidelines:
■ All adults should be assessed for risk of colorectal cancer.
■ In average-risk adults, screening should begin at age 50. In high-risk adults, screening should begin at age 40 or 10 years younger than the age at which the youngest affected relative was diagnosed with colorectal cancer.
The American College of Gastroenterology also recommends screening beginning at age 50 in average-risk adults. It also advocates screening at age 45 for African-Americans and age 40 (or 10 years younger than the age at diagnosis of the youngest affected relative) in adults with a family member diagnosed with colorectal cancer. The American College of Gastroenterology recommends colonoscopy as the preferred colorectal cancer prevention test every 10 years in average-risk and every five years in high-risk adults.
The success of any screening program, especially colorectal cancer screening, depends on the appropriate testing and follow-up. Although the effectiveness of screening in reducing mortality has been demonstrated, only 60.8 percent of adults ages 50 or older in the U.S. get screened. All of the above organizations agree that screening of average-risk adults should start between ages 40 and 50, depending on ethnicity. It is important to use a shared decision-making approach to select a screening method.
Colorectal cancer is a common disease with high incidence, prevalence and mortality. Screening for colon cancer is effective in prevention.
Based on the above information, I recommend colonoscopy every 10 years starting at age 50 for my patients with average risk of colon cancer.
Mark E. McCaulley, MD, FACP