Abstract
During the last 41 years cancer of the colon in Puerto Rico has markedly increased as reported by the Puerto Rico Cancer Registry. The etiology of this increase remains elusive, but possibilities include an increase in reporting new cases, dietary modifications, exposure to carcinogens, as well as an hereditary predisposition. The importance of Hereditary Nonpolyposis Colorectal Cancer (HNPCC) in Puerto Rico, its molecular genetics, diagnostic criteria, and management will be discussed.