Neoadjuvant Chemotherapy Followed by Interval Debulking Surgery and the Risk of Platinum Resistance in Epithelial Ovarian Cancer.

BACKGROUND: Interval debulking surgery (IDS) is an option for treating patients with advanced ovarian carcinoma. Two randomized trials have shown similar survival rates for primary debulking surgery (PDS) and IDS. One of the concerns with IDS is the potentially higher risk of inducing platinum resistance when treating patients with greater disease volume. METHODS: A retrospective review of data on 237 patients with stage IIIC and IV ovarian carcinoma who were treated at a single institution from 2000 to 2013. We analyzed the association of IDS with time to first platinum resistant relapse (TTPR); platinum-resistant disease at first relapse, defined as a platinum-free interval (PFI) after first-line chemotherapy of <6 months; and overall response rate (ORR) to chemotherapy at first platinum-sensitive relapse. RESULTS: The TTPR was 60 months, and the median TTPR was longer for the PDS (80.8 months) versus IDS group (39.3 months; p = 0.012) and for patients with residual disease (RD) ≤10 mm (80.8 months) compared with those with RD >10 mm (26.1 months; p < 0.001). In the multivariate analysis, IDS [hazard ratio (HR) 1.92; p = 0.009] and RD >10 mm (HR 1.65; p < 0.001) retained an increased risk of developing platinum-resistant disease. IDS was not associated with a greater risk of PFI <6 months at first relapse, and the ORR to platinum-based chemotherapy at first platinum-sensitive relapse was 87.2 % for patients who were treated with PDS compared with 68.0 % for those who underwent IDS (p = 0.051). CONCLUSIONS: IDS correlates with a higher risk of the development of platinum resistance.