Anastrozole and Levonorgrestrel-Releasing Intrauterine Device in the Treatment of Endometriosis: A Randomized Clinical Trial.

Abstract

Background: To study the effectiveness of an aromatase inhibitor (Anastrozole) associated to levonorgestrel-releasing intrauterine device (LNG-IUD, Mirena®) in the treatment of endometriosis.Methods: Prospective, randomized clinical trial. Setting: University Hospital (single center). Elegibility criteria: Endometriomas >3×4 cm, CA-125>35 U/mL and endometriosis symptoms. Patients: Thirty-one women randomized to anastrozole+Mirena®+Conservative Surgery(CS) (n=8), anastrozole+Mirena®+transvaginal ultrasound-guided puncture-aspiration (TUGPA) (n=7), Mirena®+CS (n=9), or Mirena®+TUGPA (n=7). Interventions: Anastrozole 1 mg/day and/or only Mirena® for 6 months; CS (ovarian and fertility-sparing) or TUGPA of endometriomas one month after starting medical treatment. Main Outcome Measures: Visual analogic scale for symptoms, CA-125 levels, ultrasound findings of endometriomas and recurrences.Results: A significant improvement in symptoms during the treatment (difference of 43%, 95% CI 29.9-56.2) occurred, which was maintained at 1 and 2 years. It was more significant in patients treated with anastrozole (51%, 95% CI 33.3-68.7). For CA-125, the most significant decrease was observed without anastrozole (73.8%, 95% CI 64.2-83.4 vs. 53.8%, 95% CI 25.7-81.6 under Mirena®+anastrozole). After CS for endometriosis, a reduction of findings of endometriomas and long-term recurrences occurred, with or without anastrozole. At 4,2±1,7 years (95% CI 3,57-4,85), 88% of the patients who underwent CS were asymptomatic, without medication or reoperation, compared to only 21% if TUGPA was performed, with or without anastrozole (p=0.019).Conclusions: Dosing anastrozole for 6 months, starting one month before CS of endometriosis, reduces more significantly the painful symptoms and delays recurrences, but has no other significant advantages over the single insertion of LNG-IUD (Mirena®) during the same time.Details of trial registration: Eudra CT System of the European Medicines Agency (London, 29-Sept-2008) Nº EudraCT: 2008-005744-17 (07/11/2008). Date of enrolment of first patient: 15/01/2009.