Primary and Acquired Platinum-resistance Among Women with High Grade Serous Ovarian Cancer

Objective: Women with primary platinum resistant (PPR) high grade serous ovarian cancer (HGSOC) are known to have a poor prognosis. Less is known regarding outcomes in patients with acquired platinum resistance (APR). The goal of this study was to evaluate survival in both PPR and APR patients.

Methods: A retrospective review of HGSOC patients diagnosed between 2000 and 2010 was performed. Descriptive statistics summarized clinical characteristics and demographics. The Kaplan-Meier method estimated progression free survival (PFS) and overall survival (OS). The association of OS and clinical factors was modeled using Cox proportional-hazards.

Results: Of the 330 patients identified, 81 (25%) had PPR. Of the remaining women, 55 (22%) developed APR. Median PFS of PPR patients was 4.2months and median OS was 17.8months. On multivariate analysis, the number of biologic agents received was the only predictor of OS. Patients with APR had a median PFS of 14.2months and a median OS of 56months. OS from the date of platinum resistance was 21.9months, though this was not different than PPR patients (p=0.19). Multivariate analysis found cancer stage and clinical trial participation to be associated with OS.

Conclusions: Platinum resistance confers a poor prognosis in the APR and PPR setting. The number of biologic agents received is the strongest predictor of OS among women with PPR. Cancer stage and clinical trial participation predicts OS in patients with APR. Providing opportunities to participate in clinical trials, especially those involving targeted therapy, should be a priority in these populations.