대한대장항문학회

Hereditary nonpolyposis colon cancer(HNPCC) accounts for 1∼6% of colorectal cancer. Mutations in the DNA mismatch repair genes(hMSH2, hMLH1 and hPMS1, hPMS2 and hMSH6) are responsible for HNPCC. To evaluate the clinical characteristics of Korean HNPCC<br>patients, analysis were performed on the 176 patients from 40 HNPCC families registered in the Korean Hereditary Tumor Registry. All the families in this study fulfilled the ICG-HNPCC criteria. The control group consisted of 1,204 patients of<br>nonhereditary colorectal cancer operated at SNUH between 1991 and 1995. The mean age of patients at diagnosis was significantly lower than the control group (44.5 vs 56.1 years old). Thirty three percent of cancers were located proximal to splenic<br>flexure compared to 23% in control group. Among the 71 patients whose pathological reports were available, 14 patients(20%) had synchronous colorectal cancer compared to 4% in control. Also 15 patients(21%) had synchronous adenomatous polyp and 3<br>patients had both the synchronous cancer and polyp. Thus, overall 26 patients (36%) had multiple colorectal cancer including polyp. The cancers in HNPCC patients were detected at significantly earlier stage than control(67% of HNPCC patients were Dukes<br>A or B compared to 48% in control). Statis tically significant difference was not observed in tumor differentiation between HNPCC and control group. In terms of treatment, 64% of patients received an extensive surgery over subtotal colectomy between<br>1995∼1997 compared to 31% in the period of 1991∼1994. In this series, we confirmed that Korean HNPCC patients have similar characteristics with western countries in that an early age of onset, a proclivity for the proximal colon and excess of<br>synchronous colorectal cancers. However, relatively low incidence of proximal colonic involvement and low rate of mucinous or poorly differentiated carcinoma differed from the reports from the western countries.<br>