Reducing the incidence and mortality of colon cancer: Mass screening and colonoscopic polypectomy

Colorectal cancer afflicts about 150,000 Americans annually, about 50,000 of whom die from the disease [1]. Established screening and surveillance colonoscopy regimens, as recommended by American and international medical societies [2,3], largely can prevent this mortality by detecting and removing premalignant colonic polyps and by detecting colon cancer at an early and curable stage [4-6]. Yet, nearly half of eligible United States patients have not undergone any form of screening for colon cancer [7,8]. Patients refuse screening because of embarrassment, fear of potential complications, reluctance to undergo invasive tests when asymptomatic, denial, and potential economic costs. Patients will become progressively harder to recruit for colon cancer screening tests as the more compliant patients have already undergone screening. The residual unscreened patients tend to be poor or ethnic minorities who have limited access to health care [9]. Although mostly because of patient factors, noncompliance also stems from physician factors. For example, most United States primary care physicians do not offer any form of colon cancer screening to eligible indigent patients [9]. This problem is not confined to America, but occurs throughout the world [10]. In a recent survey, only about one-quarter of 700 Italian general practitioners properly referred their patients for colon cancer screening, with both frequent over-referral and under-referral [11]. Under-referral results in thousands of preventable deaths in Italy per year [12]. Over-referral, such as referral for colonoscopy of average-risk patients less than 5 years after a negative screening colonoscopy, results in excessive costs without demonstrable benefits. To save patient lives and minimize costs, physicians in the United States and throughout the world must educate themselves to appropriately advocate screening colonoscopy, to answer patient misgivings about undergoing colonoscopy [13], and to follow practice guidelines [10]. Patient education by educated physicians moreover, should help eliminate patient barriers to mass screening [10]. A review of the natural history of premalignant colonic polyps and the benefits of colorectal cancer screening is important and timely. This field is changing rapidly because of breakthroughs in the pathophysiology of colon cancer and in the technology for colon cancer screening and therapy. This article reviews colon cancer with a focus on the natural history, detection, and therapy of colonic polyps, the precursor lesions of colon cancer, to help the clinician and the gastroenterologist appropriately screen and treat patients to reduce colon cancer mortality.