877PD - Clinical Outcomes of Recurrent Ovarian Granulosa Cell Tumours Treated with Letrozole: a 10-Year Retrospective Case-Series of the Royal Marsden Hospital

Abstract

ABSTRACT Aim: Granulosa cell tumour (GCT) is a rare ovarian malignancy. There is currently no consensus on the optimal management of advanced/ relapsed disease and evidence is limited. Hormonal therapy (HT) is a potential option as the majority of GCTs express steroid receptors. Granulosa cells are known to have relatively high aromatase activity. The aim of this study was to evaluate the effectiveness of letrozole, a non-steroidal aromatase inhibitor, in the management of recurrent GCTs. Methods: A retrospective analysis of patients with GCT treated at a single centre between 01/01/2002 - 31/12/2012 was performed. Patient clinical details were identified from the hospital electronic database. The primary outcome was response rate (RR); secondary outcomes included clinical benefit rate (CBR) defined as partial response and disease stabilisation ≥6 months rates and progression-free survival (PFS). Results: A total of 47 OGT patients were identified of whom 29 (61.7%) had recurrent disease. 16 patients were treated with letrozole (mean age 49.4 years [28-78], median number of previous treatments 4 [1-8], 31% FIGO stage 1c at diagnosis). Previous treatment for recurrent disease included platinum-based chemotherapy (50%), at least one surgery (75%) and HT (62.5%) with tamoxifen and/or goserelin. 50% of patients received letrozole following 4th relapse. The median follow-up was 33.5 months at the time of analysis. The RR (radiological) was 56.3% (n = 9); CBR 100%; median PFS 21.3 months (95% CI, 12.9 -29.6). At the time of analysis, the median duration of treatment was 19.45 months [8.17; 76.8]; 43.8% (n = 7) were still on letrozole. Further updated clinical outcomes will be presented. Conclusions: Significant clinical activity was achieved with letrozole in heavily pretreated GCT patients including prior HT. To our knowledge, this is the largest case series to report on the effectiveness of letrozole in recurrent GCTs. Aromatase inhibitors should be considered a valid option for advanced/ recurrent GCTs. Prospective studies will further clarify the role of aromatase inhibitors as standard of care. Disclosure: All authors have declared no conflicts of interest.