Evaluation of aromatase expression in endometrioid heterotopias and endometria in patients with external genital endometriosis

Abstract

BACKGROUND:External genital endometriosis is a multifactorial estrogen-dependent disease. Local estrogen production due to aromatase activity can play an important role in its pathogenesis, so aromatase inhibitors are considered promising drugs for the treatment of the disease. However, the data on their effectiveness are contradictory. AIM:The aim of this study was to evaluate the expression level of the aromatase-encodingCYP19A1gene in the eutopic endometrium and endometrioid heterotopies of patients with endometriosis and in the eutopic endometrium of women from the comparison group. MATERIALS AND METHODS:This study included 79 women. The main group consisted of 55 patients with endometriosis, and 24 patients without endometriosis formed a comparison group. All of the patients underwent an endometrial biopsy during surgery, with excision of endometriotic lesions performed in patients with endometriosis.CYP19A1gene expression was studied using reverse transcription real-time polymerase chain reaction. RESULTS:The data obtained confirm a high level of aromatase expression in endometriosis foci. On average, aromatase expression is increased in the eutopic endometrium of patients with endometriosis when compared to the endometrium of women in the comparison group. However, in a significant number of patients with endometriosis, aromatase is expressed in the endometrium at a low level. We did not find an association of increased aromatase expression with any clinical and anamnestic features of the studied group of women, in particular, with infertility, pain syndrome, prevalence of endometriosis, or relapses of the disease. CONCLUSIONS:Our findings highlight the heterogeneity of endometriosis and may account for the variable effectiveness of hormone-modulating therapy, in particular aromatase inhibitors.