Influence of sex and sex hormones on transplantable hepatocellular carcinoma in the rat.

Palpable subcutaneous transplants of hepatocellular carcinoma-35 appeared slightly earlier in male animals; however, the number of successful growths was no greater than that in female animals. Castration and administration of testosterone or diethylstilbestrol were performed after the transplants reached 1.0-1.5 cm in size. The carcinoma was less well differentiated histologically, had more bile pigment, grew rapidly, mestastasized sooner and killed the host quickly in castrated females given testosterone propionate. Bile was present in lung metastases. There was little difference in the growth rate in intact or castrated male or female animals. Exogenous diethylstilbestrol slowed the growth of the transplants and cause weight loss in castrated males. The weight loss was felt to be related to extensive necrosis of the carcinoma.