Chapter 7 - Steroid Hormones and Hormone Receptors in Neoplastic Diseases

Abstract

This chapter describes the role of steroid hormones and hormone receptors in promoting the growth of neoplastic diseases. There is considerable evidence that different classes of steroid hormone receptors in tumor cells are under autoregulatory control; thus, the dominant factor regulating steroid hormone receptor levels in tumor cells appears to be the cognate hormonal ligand itself. The effects of steroid hormones on cells are mediated by receptors that interact with DNA and regulate gene transcription. Estrogens have a direct mitogenic effect on breast cancer cells and shorten the duration of their cell cycle. In vivo, growth factors, and estrogen probably act in concert with other systemic mitogens to promote tumor growth. In addition to intrinsic oncogenic potential, steroid hormone receptors may be involved in the pathogenesis of cancer through their interaction with environmental toxins. Both estrogen and progesterone receptors are detectable in endometrial adenocarcinoma cells, where the level of these receptors correlates with the degree of cellular differentiation. Immunocytochemical assays of fresh frozen sections of endometrial carcinoma tissue demonstrate considerable heterogeneity in terms of the cellular distribution of estrogen and progesterone receptors.