The epidermal growth factor family in the mammary gland and other target organs for ovarian steroids.

Abstract

The influence of ovarian steroids on the growth and development of the normal mammary gland and mammary tumors in laboratory rodents is well known to the research investigator, and has emphasized the need to understand the pathways by which these compounds exert their effects on target organs. The clinical significance of the ovaries to breast cancer was evident around the turn of the century, when ovariectomy was shown to ameliorate the course of this disease in some women [1]. The high incidence of breast cancer in women in the United States and the marked reduction in incidence of this disease in women ovariectomized an early age suggest a permissive or promotional role for ovarian steroids [2, 3, 4]. Similarly, the influence of age at menarche or menopause on breast cancer risk may be explained by the duration or extent of exposure to ovarian steroids [5]. The long-term use of estrogens to relieve postmenopausal symptoms in women has already been linked with an increased incidence of endometrial carcinoma [6]. This exogenous use of natural or synthetic ovarian steroids and their antagonists for the purposes of estrogen replacement therapy, contraception, or cancer treatment and prevention has become a major health issue and dilemma, especially when we consider the millions of women treated with this category of drugs.