SHOULD ADD-BACK THERAPY FOR ENDOMETRIOSIS BE DEFERRED FOR OPTIMAL RESULTS

Add-back hormone replacement therapy has been shown to alleviate some of the hypo-oestrogenic side effects associated with gonadotrophin-rel easing hormone agonists, including demineralisation of bone. Studies o n patients with uterine fibroids have shown that concomitant add-back therapy reduced the efficacy of these agents, but that deferred admini stration was less detrimental. This trial set out to investigate if de ferred add-back therapy could offer any advantages to patients with en dometriosis compared with immediate therapy. Zoladex(TM) [goserelin ac etate (3.6 mg every 4 weeks)] was given for 24 weeks either with place bo, with medrogestone (10 mg/day) for 24 weeks (immediate add-back the rapy), or with placebo for 12 weeks followed by medrogestone (10 mg/da y) for 12 weeks (deferred add-back therapy) to 123 patients. The numbe r of responders measured using the Revised American Fertility Society score (decrease in this score of greater than or equal to 50%) was gre atest in the immediate add-back therapy group, although there were no significant differences between groups. All three treatment groups sho wed significant decreases in bone mineral density compared with baseli ne but smaller losses were generally observed in the add-back groups. A significantly smaller number of patients in the immediate add-back g roup reported hot flushes during the first 12 weeks of treatment compa red with the deferred add-back group. In conclusion, it appears that t here is no extra advantage to patients with endometriosis being treate d with goserelin in delaying the start of add-back therapy.