Intraperitoneal Intraoperative Chemotherapy in Advanced Ovarian Cancer: Rethinking the Future Beyond Complete Macroscopic Resection

Abstract

Background: The rationale for intraperitoneal chemotherapy after complete macroscopic cytoreduction (CC-0) is well-established for peritoneal surface malignancies. This study aimed to analyze prognostic factors for disease-free survival (DFS) of patients with high-grade serous ovarian cancer (HGSOC) undergoing interval CC-0 cytoreductive surgery (iCRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Methods: This retrospective multicenter study included 293 HGSOC patients treated between January 2010 and May 2023. All the patients received neoadjuvant platinum-based chemotherapy followed by CC-0 iCRS and HIPEC with cisplatin or paclitaxel. Prognostic factors for DFS were analyzed using Kaplan-Meier curves, log-rank tests, and Cox proportional hazards regression. Results: The median DFS was 23 months, with 3- and 5-year survival rates of 39 % and 29 %, respectively. The patients with a peritoneal carcinomatosis index (PCI) of 15 or lower had significantly better DFS than those with a PCI greater than 15 (24 vs 15 months; p < 0.05). Paclitaxel-based HIPEC was associated with superior DFS compared with cisplatin (25 vs 16 months; p < 0.05). Multivariate analysis showed a PCI greater than 15 related to a lower DFS (hazard ratio [HR], 1.539; p = 0.048) and paclitaxel-based HIPEC as a factor associated with better DFS (HR, 0.663; p = 0.016). The patients treated with HIPEC-paclitaxel and with a PCI of 15 or lower demonstrated the best outcomes (median DFS, 33 months). Conclusion: In HGSOC, the PCI is the most significant determinant of DFS after CC-0 iCRS and HIPEC. Paclitaxel-based HIPEC showed better outcomes than cisplatin, particularly for patients with a PCI of 15 or lower. Further prospective studies are needed to confirm the role of paclitaxel and to evaluate BRCA mutation and homologous recombination deficiency status in treatment efficacy.