The pathophysiology, clinical presentation, and （临床表现,病理生理学）.pdf

Med Clin N Am 89 (2005) 1–42 The pathophysiology, clinical presentation, and diagnosis of colon cancer and adenomatous polyps Mitchell S. Cappell, MD, PhD, FACG Division of Gastroenterology, Department of Medicine, Albert Einstein Medical Center, 5501 Old York Road, Philadelphia, PA 19141-3098, USA Colon cancer afflicts more than 135,000 patients per year in America. It kills more than 55,000 patients per year [1] and many more patients suffer morbidity from curative colon cancer surgery or chemotherapy. Recently promulgated screening and surveillance colonoscopy regimens, as recom- mended by medical professional societies (including the American Gastro- enterological Association [2], the American Society for Gastrointestinal Endoscopy [3], the American College of Gastroenterology [4], and the American Cancer Society [5,6]), and as approved by Medicare [7] and most private medical insurance companies [8] for reimbursement, can largely avoid this morbidity by colonoscopic removal of premalignant polyps [9], and can largely prevent this mortality by early detection of colon cancer at a curable stage [9–11]. Yet only about one quarter of eligible patients currently undergo any form of colon cancer screening [12]. This failure tragically results in tens of thousands of preventable deaths and even greater morbidity per annum in America. Aside from patient reluctance to undergo colonoscopy because of the invasiveness, risks, and discomfort of the test [13], a major factor in this breakdown is the failure by primary care physicians and internists to educate their patients and refer them for screening colonoscopy [14]. Contrariwise, primary care physicians and internists occasionally refer patients who are inappropriate candidates for screening colonoscopy because of age less tha