Abstract
OBJECTIVE: Describe surgical outcomes of patients undergoing HIPEC with cisplatin (C) alone or cisplatin/paclitaxel (CP), compared to interval debulking surgery (IDS) without HIPEC, and stratify disease-free survival (DFS) by treatment and homologous recombination (HR) status. METHODS: Retrospective chart review of patients with advanced ovarian cancer undergoing IDS with and without HIPEC between 2018-2024. DFS was compared using a log rank test. Cox proportional hazards model was used to test association between treatment group and recurrence. RESULTS: 74 patients were included: 20 in no HIPEC, 28 in HIPEC-C, and 26 in HIPEC-CP groups. Duration of surgery was shortest in no HIPEC group (159 ± 64 min vs HIPEC-C 377 ± 54 min vs HIPEC-CP 400 ± 48 min, p < 0.0001). Post-operatively, there was no difference in days to return of bowel function (p = 0.17) or Grade II-IV complications (p = 0.39). HIPEC-C group had longest time to discharge (4.5 ± 1.2 post-operative days vs no HIPEC 3.8 ± 1.9 vs HIPEC-CP 3.6 ± 0.9, p = 0.002). Twenty-nine (39.2 %) patients were HR deficient (HRD). Median DFS did not differ between treatment groups (no HIPEC 17.0 months vs HIPEC-C 13.87 months vs HIPEC-CP 19.25 months, p = 0.853). Median DFS was higher in HRD vs HRP (HR proficient) patients (40.5 months vs 11.4 months, HR 0.32 (95 % CI: 0.19-0.57, p = 0.0001). CONCLUSIONS: Addition of paclitaxel to cisplatin at the time of IDS with HIPEC had no effect on peri-operative morbidity. No differences in DFS were seen between treatment groups. HRD group had a significantly longer DFS, when compared to HRP. Tumor genetics and HR status likely drive response to treatment in advanced ovarian cancer.