Chemotherapy or upfront surgery for newly diagnosed advanced ovarian cancer: Results from the MRC CHORUS trial.

Abstract

5500 Background: First line treatment of advanced ovarian cancer (OC) is accepted to be primary surgery (PS) followed by adjuvant platinum-based chemotherapy (P-CT). However, the EORTC55971 trial suggested neoadjuvant chemotherapy (NACT) is an alternative, showing increased optimal debulking rates and reduced surgical complications without detriment to survival. CHORUS (CRUK 07/009) is the 2nd phase III randomized controlled trial to investigate timing of initial surgery in OC. Methods: Patients (pts) with clinical FIGO stage III-IV OC (pelvic mass, extrapelvic metastases and CA125/CEA ratio >25) were randomized to standard treatment (PS followed by 6 cycles P-CT) or NACT (3 cycles P-CT either side of surgery). CHORUS was designed to demonstrate non-inferiority of NACT, excluding a 6% absolute detriment in 3yr survival from 50% expected with PS (1-sided alpha 10%). Primary outcome was overall survival (OS) and secondary outcomes were progression free survival (PFS), toxicity and quality of life. Results: 550 women (276 PS, 274 NACT) were randomized from 74 centres (72 UK, 2 NZ) between Mar 2004 and Aug 2010. Baseline characteristics were well balanced: median age 65yrs, median tumor size 80mm, 25% FIGO stage IV, 19% WHO PS 2. Median follow-up was 3yrs, 410 pts have died. Treatment data are summarized in the Table. 3yr survival in the control arm was 32%. Intention to treat analysis showed a median OS of 22.8 months for PS vs 24.5 months for NACT (hazard ratio (HR) 0.87 in favor of NACT, 80% CI 0.76 – 0.98) and median PFS of 10.2 vs 11.7 months (HR 0.91, 0.81 – 1.02). OS results represent a 5% absolute benefit in 3yr survival for NACT to 37% and the upper 80% CI allows us to exclude a survival benefit for PS. Conclusions: NACT was associated with increased optimal debulking, less early mortality and similar survival in this poor prognosis group. CHORUS results are consistent with EORTC55971 and strengthen evidence that NACT is a viable alternative to PS. Clinical trial information: ISRCTN74802813. [Table: see text]