Genetic control of susceptibility to diethylnitrosamine and dimethylbenzanthracene carcinogenesis in rats.

The susceptibility to cancer induction after a single dose of diethylnitrosamine in male rats and a single dose of dimethylbenzanthracene in female rats was examined in the grc- strain R16 and the grc+ strain ACP, both of which have the same major histocompatibility complex genes but differ in the grc region. No tumor-promoting regimens were used, and the animals were fed only laboratory chou. The R16 males developed liver cancer and the R16 females developed breast cancer, there also were malignancies in other organs in some animals. By contrast, the ACP males did not develop any malignancies, and the ACP females had a significantly lower prevalence of malignant tumors. Thus the susceptibility to cancer in these two strains of rats has a genetic basis associated with genes in the grc region, and is independent of the carcinogen used, the action of a promoter, and the sex of the animals.