Aromatase inhibition for refractory endometriosis-related chronic pelvic pain

Objective To evaluate the use of an aromatase inhibitor for the treatment of endometriosis-related chronic pelvic pain. Design Retrospective analysis. Setting Academic medical center outpatient reproductive endocrinology clinic. Patient(s) Sixteen patients with endometriosis and chronic pelvic pain who previously failed conventional medical and/or surgical therapy. Intervention(s) Treatment with the aromatase inhibitor letrozole (2.5 mg/d) plus a gonadotropin suppressor (norethindrone acetate, 2.5 mg/d, or a combination oral contraceptive [OC]) for an average of 6 months. Main Outcome Measure(s) Pain scores were reported at each visit using a visual analogue scale from 0 to 10 (0: no pain, 10: maximum pain). Result(s) Sixteen patients were treated with an aromatase inhibitor for 180 ± 31days. The median pain score at the start of therapy was 7, and at the end of therapy it was 1.5. In the nine patients who were evaluated after discontinuing therapy, pain scores returned to pretreatment levels. We did not find any correlation between the length of treatment and the overall improvement in pain score. Conclusion(s) Letrozole plus a gonadotropin suppressor substantially improved pain symptoms in patients with endometriosis refractory to conventional therapies; however, pain recurred after treatment was completed.