Hormones and Receptors in Endometrial Cancer

The uterine endometrium is exquisitely sensitive to hormones, in particular estrogen and progesterone and to a lesser extent androgens and glucocorticoids. These hormones tightly regulate the complex functioning of the female reproductive tract and are intimately involved in controlling the growth, development, and remodeling of reproductive tissues as well as the cyclic changes that occur during the menstrual cycle. Steroids function by binding to nuclear receptor proteins that act as transcription factors to modulate the expression of genes, though many non-genomic effects for steroids have also been described. An imbalance of the hormones leads to cancer. In particular, endometrial carcinogenesis is related to overexposure to estrogen that is not balanced by the differentiating effects of progesterone and potentially other steroid hormones, including androgens and glucocorticoids. This review summarizes steroid hormone action in the endometrium, describes the relative localization of hormone receptors in the normal endometrium and in endometrial cancer, and highlights key clinical trials that have attempted to restore the balance of hormones and thus prevent recurrence of endometrial cancer. The Department of Obstetrics and Gynecology, The Carver College of Medicine, The University of Iowa, Iowa City,