Polyps of the large intestine in Aarhus, Denmark. An autopsy study.

In 336 consecutive autopsies a total of 305 tumors were recorded in the large intestine. Of these, 184 were adenomas occurring in 26% of the 196 men and 17% of the 140 women, resulting in an overall prevalence of 22%, or 15% when standardized to the world standard population (WSP). The prevalence of adenomas increased with age, and a shift from distal to proximal location occurred in the older age groups, mostly accounted for by the greater tendency to multiplicity in old age. Regardless of age 57% of the cases of adenomas could have been identified by flexible sigmoidoscopy. The prevalence of hyperplastic polyps was 13%, and an association between these and adenomas was found. Five adenocarcinomas occurred in the study. With some exceptions, which are discussed in detail, the results are in accordance with studies from other countries with a high incidence of colorectal cancer and similar socioeconomic composition. The study supports the theory of the adenoma-carcinoma sequence.