[Epidemiologic study of cancer of the colon and rectum in the health area of the Nalón valley (Asturias, 1978-1986)].

: An epidemiological study was made of malignant tumors of the colon and rectum in the Nalon valley health district (Asturias, Spain). The study period comprehend from 1978 to 1986, inclusive. The population studied, 103,000 hab., has been stable over the last 10 years, and is grouped into well defined sectors: industrial-mining activities and agricultural-livestock raising. The total number of cases was 275 patients, for a mean annual incidence (IMA) of 29.7/10(5) hab., making this a zone of high risk of the disease. Also analyzed are the clinical characteristics, diagnostic methods ant therapeutic measures, as well as the epidemiological distribution, a higher incidence being found in the industrialized zone than in the agricultural zone (p less than 0.05).