[Epidemiology of rectal cancer: current findings].

The exact incidence of rectal cancer in Belgium is not known, due to the absence of an operational national cancer registry. Mortality data however are well documented by death certificates. Annual rectal cancer death rates reach 20 and 13 per 100,000 for men and women respectively in the age category from 45 to 74 years (data from 1981). When similar data obtained for the years 1968 to 1983 are being compared, a significant decrease of rectal cancer mortality can be observed, at a rate of 2.6% annually. Such a decrease is not seen for colon cancer, of which the respective annual death rates are 41 and 33 per 100,000. Absolute figures for the whole Belgian population in 1984 were 3204 deaths due to colorectal cancer, with 2307 cases for colon and 897 cases for rectal cancer. In regions where incidence data are available, it is found that the cumulative risk of colorectal cancer between birth and the age of 75 can reach more than 5% in industrialized countries. Recent incidence data confirm the significant decrease in rectal cancer occurrence.