The effect of hormones on endometriosis development

Endometriosis is a common gynecological condition in which tissue that is histologically similar to the endometrium with glands and/or stroma grows outside the uterine cavity and can lead to pelvic pain, dysmenorrhea and infertility. Many aspects of female reproductive function are strongly influenced by genetic factors and numerous studies have attempted to identify susceptibility genes for disorders affecting female fertility such as endometriosis. The importance of steroid hormones on endometriosis is unquestionable. The disease is most prevalent in women of reproductive age and regresses after menopause and its occurrence before menarche has not been reported. Sex steroids, estrogen and progesterone, are mainly produced in the ovaries and they regulate the growth of endometrial tissue, basically by stimulating and inhibiting cell proliferation, respectively. In addition, estrogen plays an important role in the regulation of cyclic gonadotropin release and in folliculogenesis. Numerous studies have been conducted to demonstrate the interaction of hormone and their receptors with endometriosis with conflict results. Besides, environmental chemicals, known as endocrine disruptors, have the capacity to mimic, block or modulate the endocrine system through the interaction with steroidal receptors. Recently evidences have proposed a putative role for ubiquitous environmental contaminants in the occurrence of endometriosis. Here, we reviewed significant articles regarding the interaction among endometriosis, hormones and genetic polymorphic variants.