Summary of Conference Plenary Sessions

Abstract

As an introduction to the discussion of steroid hormone action and cancer, Dr. Roy Hertz presented data derived from studies of experimental animals and humans on tumors that are induced by steroids as well as those secreting steroids, and those that are responsive to steroids. A variety of estrogen-induced tumors were described; high tumor strains of various species are found to be more susceptible to tumor induction by exogenous steroids than are low tumor strains. Dosage and duration of exposure also play a critical role in tumor induction by steroids. For example, there is a very critical period during organogenesis of the female genital tract for the induction of vaginal adenosis and possibly carcinoma. Steroid-producing tumors are restricted to those organs that normally synthesize steroids such as ovary, testis and adrenal. In the adrenal cortex the growth potential of the neoplastic as well as the normal adrenocortical cell is readily separable from its steroidogenic function. Hormone-responsive tumors provide examples of tumors that are responsive to endocrine therapy. Notable among these are the tumors of the breast and the endometrium which respond to hormonal treatment. A paradoxical case history of DES therapy of breast cancer was presented. Some breast cancers grow in response to estrogens, whereas others undergo regression with DES therapy.