A 20-YEAR REVIEW OF MALIGNANT COLORECTAL NEOPLASMS AT UNIVERSITY-COLLEGE HOSPITAL, IBADAN, NIGERIA

PURPOSE: Colorectal malignancies are less common in developing than de veloped nations because of lower per capita income and higher dietary fiber consumption. This clinicopathologic study attempts to determine changes in the pattern of these neoplasms in Ibadan, Nigeria, during t he last two decades. METHODS: The present study is based on the clinic al Cancer Registry records and gross and morphologic surgical patholog y findings of 526 patients with histologically verified malignant colo rectal neoplasms received in the Department of Pathology, University C ollege Hospital, Ibadan, between 1971 and 1990. RESULTS: Colonic malig nancies increased by 81 percent, whereas rectal malignancies decreased 16.1 percent in frequency (P < 0.05). The modal ages were 55 to 60 ye ars and 45 to 50 years for colonic and rectal neoplasms, respectively, in contrast to reported peak occurrence in the seventh decade among C aucasians. Colonic neoplasms were predominantly right-sided (34.3 perc ent cecal), abdominal mass and pain being major clinical manifestation s. This differs from the pattern in American Negroes, among whom colon ic carcinomas are predominantly left-sided, dyschezia being an importa nt presentation. As in most other studies, adenocarcinomas were the pr edominant neoplasms. CONCLUSIONS: Further work is required to determin e prognostically significant features of colorectal cancer in our envi ronment.