Colon cancer screening is for everyone

Colorectal cancer is the fourth most common new cancer diagnosis (excluding skin) in the United States with lifetime incidence rates of approximately 4%. With the recognition that cancers and large polyps may cause occult gastrointestinal bleeding, randomized trials in the early 1990s demonstrated that screening by fecal occult blood testing reduced colorectal cancer mortality. Subsequent investigations demonstrated that screening flexible sigmoidoscopy reduced both colorectal cancer incidence and mortality. The landmark study by Lieberman et al first demonstrated the high rate of adenomatous polyps and high-grade lesions including cancer in average risk asymptomatic individuals undergoing screening colonoscopy. In this study principally of Caucasian males in a Veterans Administration Hospital system, tubular adenomas were identified in 27%; higher risk lesions in 9%, and invasive cancer in 1%. Subsequent studies have now established that colonoscopy screening with polypectomy is associated with a reduction in colorectal cancer incidence by 40% and mortality by 60%. Based upon these and a wealth of other data, colorectal cancer screening by colonoscopy was covered by Medicare in 1998 rapidly followed by widespread adoption. The most recent recommendations from the US Preventative Task Force suggest screening beginning at age 45-50 years in average risk individuals.