Systematic review of the effects of aromatase inhibitors on pain associated with endometriosis

Objective  To assess the effects of aromatase inhibitors in women symptomatic of pain with endometriosis.
Design  A systematic review of published literature.
Material and methods  We conducted a comprehensive literature search to identify all the published observational and randomised studies evaluating the efficacy of aromatase inhibitors on pain associated with endometriosis. A combination of keywords was used to identify the maximum number of relevant citations in MEDLINE, EMBASE, CINAHL and the Cochrane Database.
Outcome  Pain relief, lesion size and quality of life.
Results  There were eight studies (137 women) evaluating outcomes of aromatase inhibitors. In case series/reports (seven studies, 40 women), aromatase inhibitors combined with progestogens or oral contraceptive pill or gonadotrophin-releasing hormone (GnRH) analogues reduced mean pain scores and lesion size and improved quality of life. An RCT (97 women) demonstrated that aromatase inhibitors in combination with GnRH analogues significantly improved pain ( P < 0.0001) compared with GnRH analogues alone together with significant improvement in multidimensional patient scores ( P < 0.0001). There was no significant reduction in spine or hip-bone densities.
Conclusion  Aromatase inhibitors appear to have a promising effect on pain associated with endometriosis, but the strength of this inference is limited due to a dearth of the evidence available.