Abstract
This retrospective study evaluated the impact of neoadjuvant chemotherapy (NACT) cycle number and total chemotherapy (TCT) cycle number on survival and surgical outcomes in patients with advanced epithelial ovarian cancer undergoing interval debulking surgery (IDS). A total of 115 patients with FIGO stage III-IV ovarian cancer treated with NACT followed by IDS were included and categorized by NACT cycle number (2-4 vs. ≥ 5) and TCT cycle number (≤ 9 vs. > 9). The number of NACT cycles showed no significant association with progression-free survival (PFS, 19.0 vs. 23.0 months, HR = 0.780, 95% CI [0.457-1.332], P = 0.363), overall survival (OS, 42.0 vs. 74.0 months, HR = 0.572, 95% CI [0.277-1.182], P = 0.131), or surgical outcomes, including optimal debulking rate (84.7% vs. 75.0%, P = 0.192) and combined surgery rate (33.9% vs. 32.1%, P = 0.841). In the suboptimal debulking group (n = 23), patients who received more than 9 TCT cycles had significantly improved OS (40.0 vs. 16.0 months, HR = 0.046, 95% CI [0.006-0.364], P = 0.004) and a trend toward better PFS (15.0 vs. 9.0 months, HR = 0.143, 95% CI [0.020-1.030], P = 0.054). In the high-grade serous carcinoma (HGSC) subgroup (n = 81), survival outcomes were significantly influenced by cytoreduction status (OS: not reached vs. 26.0 months, P < 0.001), while neither NACT nor TCT cycles showed a significant survival benefit. Overall, the number of NACT cycles did not appear to influence survival or surgical outcomes in patients undergoing NACT followed by IDS. Optimal cytoreduction remained the most important prognostic factor, whereas extended TCT cycles may offer a survival benefit in patients with suboptimal cytoreduction.