대한대장항문학회

Approximately 5 to 6 percent of total colorectal cancer burden is accounted for by<br>hereditarynonpolyposis colorectal cancer (HNPCC). A HNPCC is comprised of the<br>following two classification: 1) Lynch syndrome I, a hereditary nonpolyposis site-specific<br>colorectal cancer, which shows an autosomal dominant inheritance: an early age onset:<br>an increase in the synchronous or metachronous colorectal cancer: and a site specific<br>colorectal cancer: and 2) Lynch syndrome Ⅱ, the cancer family syndrome, which shows<br>all the characteristics indicated above and associated extracolonic adenocarcinoma as<br>well, Particulary an endometrial carcinoma. Because HNPCC is diagnosed only by family<br>history, minimum criteria of HNPCC was suggested by International Collaborative Group<br>on HNPCC. Minimum criteria is that 1) at least three relatives should have histologically<br>verified colorectal cancer: one of them should be a first degree relative to the other two,<br>familial adenomatous polyposis should excluded, 2) at least two successive generation<br>should be affected, 3) in one of the relatives colorectal cancer should be diagnosed under<br>50 years of age.<br>We have established the Korean Hereditary Colorectal Cancer Registry on basis for<br>secondary prevention of colorectal cancer. In order to register the patients of HNPCC,<br>we have reviewed the medical records of colorectal patients operated in SNUH from<br>1985 to 1990. The first case of HNPCC suitable for the minimum criteria is introduced<br>and the general concept of HNPCC is reviewed in this article.<br>