ESTABLISHMENT OF A HEREDITARY NONPOLYPOSIS COLORECTAL-CANCER REGISTRY

INTRODUCTION: Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant condition characterized by early age of onset color ectal cancer, right-sided predominance, excess of synchronous and meta chronous colonic neoplasms, and extracolonic cancers. The purpose of t his study is to report clinical characteristics of HNPCC families in o ur registry. METHODS: This is a retrospective review of medical record s of patients With a significant history of colorectal cancer and inte rviews with their families. RESULTS: Three hundred one people with can cer in 40 HNPCC families were identified. In 284 of 301 (94 percent) p eople, 363 cancers were identified. Colorectal cancer only was identif ied in 182 people (64 percent) and, in conjunction with extracolonic t umors, in another 31 people (11 percent). Extracolonic cancer alone wa s noted in 71 people (25 percent). Median age at diagnosis of colorect al cancer was 48 (range, 17-92) years. In patients with documented pat hology, right-sided tumors predominated (55 percent), synchronous and metachronous tumors were noted in 33 percent, and synchronous or metac hronous adenomas were documented in 51 percent of people. Generational anticipation was also noted. CONCLUSION: This study demonstrates and confirms characteristics that have been described in HDPCC. Namely, ea rly age of onset of colorectal cancer, right-sided predominance, multi ple synchronous and metachronous neoplasms, increased extracolonic can cers, and generational anticipation.