Clinical characteristics of Taiwanese hereditary non-polyposis colorectal cancer kindreds

Background and purpose: The prevalence of colorectal cancer in Taiwan has increased gradually in recent years. Around 5% to 15% of colorectal cancer is hereditary, and hereditary nonpolyposis colorectal cancer (HNPCC) is the most common form of hereditary colorectal cancer. This study aimed to determine the clinical characteristics of Taiwanese HNPCC kindreds. Patients and methods: We reviewed the chart records of all HNPCC kindreds followed-up in our hospital during the period from 1996 to 1999. Their clinical characteristics were recorded and analyzed. Results: There were 10 families, including a total of 202 persons, who met the Amsterdam criteria for HNPCC. Fifty-two persons in these families had a diagnosis of cancer, including 26 women and 26 men. There were 40 colorectal cancers, five endometrial cancers, five gastric cancers, two ovarian cancers, two hepatocellular carcinomas, and one each of lung cancer, breast cancer, thyroid cancer, and pancreatic cancer (six patients had two cancers). The mean age at cancer diagnosis was 42.1 years. Among the 12 occurrences in 11 colorectal cancer patients with complete clinical and pathological findings, most cancers (67%) were located proximal to the splenic flexure (right-side colon). One patient had metachronous colorectal cancer. Conclusions: This is the first report of the general clinical characteristics of Taiwanese HNPCC. The clinical characteristics of HNPCC in Taiwan were similar to those in Western countries. The genetic bases of Taiwanese HNPCC patients remain to be determined.