Estrogen, progesterone and Ki-67 receptors expression in female to male transgender patients undergoing androgen therapy

Abstract

Introduction: The female to male transsexual patients use androgens for a prolonged period and often without any medical supervision. Endogenous androgens have inhibitory effects on breast tissue, while exogenous testosterone may exert an indirect effect on the breast because of its aromatization into estrogen and it may even increase the risk of breast cancer. The Ki-67 is one of the most used antibodies for evaluation of cell proliferation. Objectives: Evaluate the expression of estrogen and progesterone receptors and Ki-67 expression in breast tissue of female to male transsexuals, biological women and men with gynecomastia. Methods: The study consists of a case series of 17 patients, 5 transgender submitted to adenomastectomy as part of their treatment at the Service to Transgenders provided by the “Hospital das Clínicas” of the Federal University of Goiás, 4 women who underwent breast reduction and 8 biological men that underwent surgery for gynecomastia. All surgical specimens were evaluated by immunohistochemistry. Results: The transsexuals had a lower rate of expression of estrogen and progesterone receptors compared with biological men and women, and in all patients using androgen the expression of Ki-67 was ≤1%. The highest rate of expression of Ki-67 was 4.18% in a man with gynecomastia. Conclusion: The expression of estrogen and progesterone receptor is lower in female to male transsexual patients who used androgens in relation to biological men and women. The rate of expression of Ki-67 is also lower in transsexuals.