Introduction/Background In advanced ovarian cancer, randomized data showed that hyperthermic intraperitoneal chemotherapy(HIPEC) after interval debulking surgery(IDS) determined improvement in both progression free(PFS) and overall survival (OS). However, data include only patients with FIGO stage III disease receiving ≤ IV cycles of neoadjuvant chemotherapy (NACT). We aimed to assess perioperative outcomes and PFS of FIGO stage IV and/or patients receiving up to VI cycles of NACT undergoing IDS+HIPEC.

Methodology This study included prospectively collected cases from 01/01/2019 to 31/07/22.Patients were suitable for HIPEC if: age>18 but≤75 years, Body Mass Index(BMI)≤ 35 kg/m2, ASA score≤ 2,FIGO stage III/IV epithelial disease treated with up to 6 cycles of NACT, residual disease at IDS<2.5 mm. Participation to clinical trials and uncontrolled medical conditions were exclusion criteria.

Results 205 patients were included. 76 (37.1%) had FIGO stage IV disease and 44 (21.5%) received >4 cycles of NACT. No significant difference was found in patients’ and disease’ characteristics between FIGO Stage III and FIGO Stage IV cases, while rate of stable disease after NACT (p=0.004), mean surgical complexity score (SCS) at IDS(p=0.001) and bowel resection rate(p=0.046) were higher in patients undergoing delayed IDS. No difference in both perioperative outcomes and complication rate were identified among the populations, however a trend towards a higher rate of severe postoperative complications was shown in case of delayed IDS(p=0.07) and FIGO stage III disease(p=0.052), the latter remaining the only independent risk factor for severe post-operative complications at multivariate analysis (p=0.02). No difference in PFS was identified neither between FIGO stage III and FIGO Stage IV patients(p=0.44), nor between patients receiving 3–4 cycles vs >4 cycles of NACT(p=0.85).

Conclusion In relation to the absence of additional complications and positive survival outcomes, we offer a background to consider the use of HIPEC in selected FIGO stage IV patients and women receiving >4 cycles of NACT.

Disclosures none