COLITIS AND COLON-CANCER IN COTTON-TOP TAMARINS (SAGUINUS-OEDIPUS OEDIPUS) LIVING WILD IN THEIR NATURAL HABITAT

The cotton-top tamarin is a nonhuman primate noted for susceptibility to juvenile onset colitis and subsequent colon cancer. About 80% devel op colitis in captive environments outside the tropics. The aim was to determine the prevalence of colitis and colorectal cancer in tamarins living wild in their tropical habitat. Endoscopic biopsy was used to compare severity of colitis, inflammatory/immune cell densities, mucos al dysplasia, and occurrence of cancer in wild tamarins in a tropical habitat with tamarins living captive in a temperate climate. Six colon biopsies from each of 69 captives showed severe colitis in 64.5% of b iopsies and moderate colitis in 19.5%. Severe colitis was not found in 88 wild tamarins; 13% had moderate colitis. Densities of polymorphonu clear leukocytes, plasma cells, and mononuclear cells in the lamina pr opria were related directly to the severity of four grades of colitis (normal, mild, moderate, and severe). Histologic or gross signs of car cinoma were detected in 12 captives and low- or high-grade dysplasia i n 15. Neither cancer nor dysplasia was found in any of the wild tamari ns. The observations suggest that colitis and cancer in the tamarin mo del are linked to environmental factors.