Optimal Time Interval Between Neoadjuvant Platinum-based Chemotherapy and Interval Debulking Surgery in High-grade Serous Ovarian Cancer

Abstract BACKGROUND There is limited data on the optimal time interval between the last dose of neoadjuvant chemotherapy (NACT) and interval debulking surgery (IDS) in high-grade serous ovarian carcinoma (HGSC). METHODS We retrospectively identified patients with stage IIIC/IV HGSC who received NACT followed by IDS during a 15-year period (January 2003-December 2018) in our Institution that is certified by the European Society of Gynecologic Oncology (ESGO) as a center of excellence for the treatment of ovarian cancer. RESULTS Overall, 115 patients with HGSC stage IIIC/IV were included. Median age of diagnosis was 62.7 years (IQR: 14.0). 76.5% (88/115) of patients were diagnosed with IIIC HGSC and 23.5% (27/115) with IV HGSC. Median PFS was 15.7 months (95% CI: 13.0–18.5) and median OS was 44.7 (95% CI: 38.8–50.5). Patients were categorized in groups according to time interval from NACT to IDS (< 4 weeks (group A); 4–5 weeks (group B); 5–6 weeks (group C); >6 weeks (group D). Patients with a time interval IDS to NACT ≥ 4 weeks had significantly shorter PFS ( p = 0.004) and OS ( p = 0.002). Median PFS was 26.6 months (95% CI: 24–29.2) for patients undergoing IDS < 4 weeks after NACT versus 14.4 months (95% CI: 12.6–16.2) for those undergoing IDS later ( p = 0.004). Accordingly, median OS was 66.3 months (95% CI: 39.1–93.4) versus 39.4 months (95% CI: 31.8–47.0) in the < 4 week versus > 4 week time interval NACT to IDS groups ( p = 0.002). On multivariate analysis, short time interval (< 4 weeks) from NACT to IDS was an independent factor of PFS ( p = 0.004) and OS ( p = 0.003). CONCLUSION We have demonstrated that performing IDS within 4 weeks after NACT may be associated with better survival outcomes. Multidisciplinary coordination of ovarian cancer patients is required to avoid any unnecessary delays.