SMALL-BOWEL CANCER IN WESTERN CANADA

Based on incident cases of small intestinal cancers in the four wester n Canadian provinces reported in the population-based cancer registrie s of British Columbia, Alberta, Saskatchewan and Manitoba we evaluated the descriptive epidemiological characteristics such as age, sex and subsite distribution of adenocarcinomas, carcinoids, lymphomas and sar comas for the period 1975-1989. The distribution of adenocarcinomas, c arcinoids and lymphomas presented a clear trend along the length of th e small bowel. Most of the adenocarcinomas (54.7%) occurred in the duo denum and their relative frequency decreased in aboral direction: 29.9 % in the jejunum and 16.0% in the ileum. The carcinoids showed an oppo site trend, an increasing relative frequency in aboral direction: 3.9% in the duodenum, 9.2% in the jejunum and 86.7% in the ileum. Lymphoma s were more frequent in the ileum (49.5%) compared to jejunum (29.4%) and duodenum (21.0%). Most sarcomas occurred along the jejunum (46.7%) . The mean and median ages of lymphoma and sarcoma patients were signi ficantly lower compared to adenocarcinoma and carcinoid cases. There w as no difference in mean and median age by gender in the adenocarcinom a and carcinoid categories, but in the lymphoma and sarcoma groups mal es were significantly younger than females.