Timing matters: Surgery-to-chemotherapy interval and outcomes in ovarian cancer.

Objective: To assess the association of the time interval between cytoreductive surgery and the initiation of adjuvant chemotherapy on treatment success in epithelial ovarian cancer.

Methods: A retrospective single center cohort study of patients diagnosed with high grade epithelial ovarian cancer between 2011 and 2023. Patients received either primary cytoreductive surgery followed by chemotherapy or neoadjuvant chemotherapy followed by interval cytoreductive and additional chemotherapy. Chemotherapy regimens were platinum based and included carboplatin and paclitaxel; Bevacizumab or Olaparib were added per guidelines. Time to chemotherapy (TTC) was categorized into ≤28, ≤35, and ≤42 days. Primary outcomes were overall survival (OS) and progression-free survival (PFS), analyzed using hazard ratios and 95 % confidence intervals.

Results: The study included 197 women with high grade epithelial ovarian carcinoma. Median OS and PFS were 29.5 and 15.1 months, respectively. Average TTC was 46.1 days with a median of 36 days. Time to chemotherapy interval less than 28 days showed a statistically insignificant trend for improved OS compared to TTC higher than 28 days with HR 1.54 (0.98-2.42) and p = 0.06. A subgroup analysis of women within this group demonstrated a significantly improved OS in patients diagnosed with stage IIIA to IVB and patients that underwent interval cytoreductive procedure (HR 1.80 [1.13-2.87], p = 0.004, HR 2.5 [1.41-4.43] p = 0.002, respectively).

Conclusions: Initiating chemotherapy within 28 days following cytoreductive surgery, may contribute to improved overall survival in ovarian cancer, particularly in patients with advanced-stage disease and patients underwent interval cytoreductive surgery.