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

Abstract

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 gonadotrophinreleasing 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.

Antiproliferative effects of anastrozole, methotrexate, and 5-fluorouracil on endometriosis in vitro and in vivo

“…Anastrozole is a type II aromatase inhibitor, which reversibly binds to the active enzyme site and dramatically decreases circulating estrogen levels (29). Its use in the treatment of endometriosis has been motivated by the overexpression of aromatase in endometriotic lesions and eutopic endometrium of women with endometriosis (2, 4), responsible for a local estrogen production and a resistance to GnRH analogues and oral progestins.…”

Aromatase inhibitor therapy in a cystic fibrosis patient with thoracic endometriosis

“…5 Aromatase is a key enzyme in all estrogen synthesis, helping convert androstenedione and testosterone into estrone and estradiol, respectively, in a rate limiting step. 5,7,8 It is known that aromatase is expressed in high levels in endometriosis implants 5,7,8 and has been suggested that endometriosis lesions over-express aromatase, 6,8 thus securing their own estrogen supply, which is in turn suppressed by AI therapy. Takayama and colleagues were the first to report successfully treating refractory endometriosis after a hysterectomy and bilateral salpingo-oophorectomy in a postmenopausal woman with an AI in 1998.…”

“…5 One randomized controlled trial showed that using AIs with GnRH analogues significantly improved pain scores compares to GnRH analogues alone, as both ovarian and extra-ovarian estrogen production was inhibited. 7 Another study showed that a GnRH analogue combined with anastrozole lengthened the pain free interval (35 vs 7.5% recurrence rate in the first 24 months). 6 Common side effects of AI therapy include headache, nausea, and diarrhea, but compared to GnRH agonists, hot flashes are milder and not as frequent.…”

Traitement de l’endométriose par les inhibiteurs de l’aromatase : efficacité thérapeutique et conséquences osseuses

“…Les é tudes rapporté es tendent à suggé rer l'efficacité des anti-aromatases dans le traitement des endomé -trioses sé vè res. Bien qu'il n'y ait qu'une seule é tude randomisé e, de nombreux auteurs pensent que les anti-aromatases sont prometteurs [35]. En 2009, l'é quipe de Bedaiwi a é tudié le lé trozole associé à un traitement par agoniste de la GnRH chez neuf patientes atteintes d'endomé triose.…”