CARCINOMA OF COLON IN A RAT

A spontaneous carcinoma of the colon in a rat was encountered during a routine toxicity test on a food additive (Howflex GBP). Colonic carcinomas form a very small proportion of the spontaneous neoplasms reported in rats. However, under conditions of experimental carcinogenesis, such tumours occur readily. In the human, the proportion of spontaneous colon carcinoma is considerably higher than in other mammals. It is thought that this difference may be due to the susceptibility of man to polyposis and ulcerative colitis, of genetic or other origins, which are known to predispose to carcinoma. It is also suggested that, under certain conditions, viral agents may be involved in the aetiology of the human lesion. © 1969.