Incidence and histological features of colorectal cancer in the Northern Cape Province, South Africa.

Abstract

The purpose of this study was to determine the incidence of colorectal cancer (CRC) in the Northern Cape province of South Africa, and to identify patients with histological and demographic features suggestive of hereditary non-polyposis colon cancer (HNPCC). This is a retrospective review of all cases of primary adenocarcinoma of the colon or rectum diagnosed by the two pathology laboratories operating in the Northern Cape between January 2002 and February 2009. Demographic data were collected, as well as pathological staging of the tumours and histological features suggestive of HNPCC (according to the revised Bethesda guidelines for microsatellite instability testing). Population census data for the Northern Cape were obtained from Statistics South Africa. The annual incidence of CRC in the Northern Cape was 3.7/100,000 population (3.5/100,000 for men and 3.9/100,000 for women). The median age at which colorectal cancer was diagnosed was 59 years (range 16-90 years). On pathological and demographic criteria, 75/206 (36%) of the patients met at least one of the criteria of the revised Bethesda guidelines for microsatellite instability testing. CRC is rare in the Northern Cape, and one-third of the patients had demographic or tumour histological features suggestive of HNPCC.