Optimal Time Interval between Neoadjuvant Platinum-Based Chemotherapy and Interval Debulking Surgery in High-Grade Serous Ovarian Cancer

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.

Results: Overall, 115 patients with stage IIIC/IV HGSC were included. The median age of diagnosis was 62.7 years (IQR: 14.0). A total of 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 months (95% CI: 38.8-50.5). Patients were categorized in groups according to the 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 vs. 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) vs. 39.4 months (95% CI: 31.8-47.0) in the <4 week vs. >4 week time interval NACT to IDS groups (p = 0.002). On multivariate analysis, the 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 four weeks after NACT may be associated with better survival outcomes. Multidisciplinary coordination among ovarian cancer patients is required to avoid any unnecessary delays.