Inhibition of growth of a transplanted adrenal cortical tumor by sex steroids.

Adrenal cortical carcinomas may be induced by early castration of male or female CE (~ , ~8) or BALB/c (6) mice. Such tumors are often hormonally dependent, i.e., they show faster growth as transplants in castrated than in intact hosts (8, 18). These dependent tumors enter a dormant, or latent, period of 1 or more months after intraocular transplantation, followed by a shorter one during which increased vascularity and moderate enlargement take place (post-latency). Subsequently, active and continuous growth occurs. Administration of testosterone to the hosts at this time inhibits further growth of the transplants and often induces regression to the post-latency or latency status (8). This action of the steroid may be direct or it may be mediated through the output of pituitary trophic hormones. This report covers the results of our study of the action of estrogen and progesterone, given systemically, and of testosterone, given either systemically or locally, upon transplants of a dependent adrenal cortical tumor.