دانلود رایگان مقاله انگلیسی تست ژنتیک و سرطان روده زودرس - الزویر 2018

Although there have been encouraging decreases in the overall incidence of colorectal cancer (CRC) in the United States, a discouraging rise in incidence among those under 50 years has emerged.1 This increase has ranged from 1.0% to 2.4% annually, and curiously, most of these early onset cases have been localized to the distal colon and rectum. The precise etiologic factors underlying this trend have yet to be elucidated.

Genetic risk factors can predispose to early onset colon cancer, and recognizing these hereditary colon cancer syndromes is critical to the management of affected individuals and their family members. Since the cloning of the APC gene that underlies the familial adenomatous polyposis syndrome in 1991, there has been an explosion in the number of genes (now >20) linked to hereditary colon cancer risk.2 The best understood are the high-penetrance genes associated with the classic Mendelian syndromes: Lynch and familial adenomatous polyposis. Many other genes that exhibit moderate penetrance are not as well-understood, and the associated cancer risks remain incompletely defined. On a practical level, most known genes associated with increased CRC risk are now captured on gene “panel” tests, although even more comprehensive panels that include genes associated with all cancer types are also available.