Continuing chemotherapy beyond 6 cycles increases the chances of complete cytoreduction surgery in patients with advanced ovarian cancer

Objective: To evaluate the impact of receiving more than 6 cycles of NACT on survival outcomes and chemotherapy-related toxicity in patients with advanced epithelial ovarian cancer (AOEC) ineligible for primary debulking surgery. Methods: This retrospective, monocentric, observational study analyzed AEOC patients who received at least 6 cycles of NACT followed by IDS. They were grouped by number of NACT cycles (6 vs ≥ 7) and cytoreduction rate (CC0 vs CC ≥ 1), with a non-surgical group for comparison. Results: A total of 335 patients were evaluated over a 20-year period. Pre-surgical variables were similar across groups, except for older age (p < 0.001) and higher Peritoneal Cancer Index (PCI) (p = 0.04) in the non-surgery cohort. Chemotherapy-related toxicities led to delays in subsequent NACT cycles, mainly in the non-surgery group (p = 0.02). After a median follow-up of 67.7 months, patients with CC0 demonstrated the longest median progression-free survival (PFS): 22 months (NACT=6) vs 21 months (NACT≥7). In CC ≥ 1 patients, PFS was 15 months (NACT=6) and 19 months (NACT≥7), while the non-surgery group had 10 months. CC0 was the primary predictor of overall survival (OS). Patients with CC0-NACT=6 had a median OS of 59 months, compared to 40 months for CC0-NACT≥7 group (p = 0.4), while patients with CC≥1, both NACT=6 and NACT≥7 presented a median OS of 27 months. Achieving CC0 after NACT≥7 significantly improved survival compared to NACT=6-CC≥1 (HR = 1.71, p = 0.019 for PFS; HR = 2.1, p = 0.009 for OS). Conclusions: Extending NACT beyond 6 cycles may benefit selected patients by enhancing cytoreduction rates and survival without increasing toxicity.