A review article published in the Journal of Ovarian Research focused on the application of aromatase inhibitor drugs in several gynecological disorders including endometriosis. The study is entitled “Use of aromatase inhibitors in practice of gynecology” and was conducted by researchers at the Turgut Ozal University, the Cengiz Gokcek State Hospital and the Ersin Arslan State Hospital in Turkey.
Estrogen is one of the main steroid hormones involved in the normal female physiology and reproduction, primarily produced in the ovaries of women in reproductive-age. The enzyme aromatase plays a crucial role in the synthesis of estrogens from androgens (testosterone and androstenedione) in a process called aromatization. This process can be blocked by aromatase inhibitors.
In the study, researchers assessed the use of aromatase inhibitors in several gynecological conditions, including endometriosis. Endometriosis is a gynecological disorder in which the tissue that normally lines the inside of the uterus (called endometrium) grows outside the uterus, usually in the abdominal cavity, where it can form lesions and cysts, scarring organs like the ovaries, bladder and rectum. The tissue, although displaced, still continues to act normally as inside the uterus, so it thickens, breaks down and bleeds with each menstrual cycle. Endometriosis can be a painful disorder, causing inflammation and very heavy periods. It is estimated that 5 to 10% of women in reproductive age suffer from this condition and it can cause infertility in up to 50% of the women. Endometriosis is an estrogen-dependent disease.
Aromatase inhibitors are able to effectively decrease the levels of circulating estrogens. However, they also cause an increase in follicle-stimulating hormone (FSH), a hormone that regulates growth, development, pubertal maturation and reproduction. Increased levels of FSH have a stimulatory effect on the growth of ovarian follicles, potentially leading to an increased risk of ovarian cysts and bone loss due to aromatase inhibitors’ prolonged use. In order to avoid these effects, aromatase inhibitors are combined with a progestin, a combination of oral contraceptive, or a GnRH (gonadotropin-releasing hormone) analogue making them suitable for long-term use.
In this way, aromatase inhibitors have been successfully applied in the management and treatment of pelvic pain associated with endometriosis, and have also been shown to reduce the size of endometriomas, a type of cyst formed when endometrial tissue grows in the ovaries. Overall, aromatase inhibitors can improve the quality of life in patients with endometriosis.
The research team concluded that aromatase inhibitors are promising therapeutic agents for estrogen-dependent diseases like endometriosis. However, the team suggests that further studies with larger cohorts of patients should be conducted to generate robust data to support the efficacy of aromatase inhibitors.