Effects of neoadjuvant hyperthermic intraperitoneal chemotherapy on chemotherapy response score and recurrence in high‐grade serous ovarian cancer patients with advanced disease: A multicentre retrospective cohort study

Abstract Objective To investigate whether the combination of neoadjuvant hyperthermic intraperitoneal chemotherapy (NHIPEC) plus intravenous neoadjuvant chemotherapy (IV NACT) has superior efficacy to IV NACT alone. Design Retrospective cohort study. Setting Two tertiary referral university hospitals. Population Patients with ovarian cancer who received NACT‐interval debulking surgery (IDS) between 2012 and 2020. Methods The tumour response to NACT was evaluated with the chemotherapy response score (CRS) system. Survival outcomes were compared. Main outcome measures CRS 3, progression‐free survival (PFS), and overall survival (OS). Results In total, 127 patients were included, and 46 received NHIPEC plus IV NACT. The addition of NHIPEC was independently associated with an increased likelihood of CRS 3 ( p = 0.033). Patients who received NHIPEC + IV NACT had significantly improved PFS compared with those who received IV NACT alone (median PFS: 22 versus 16 months, p < 0.001). The use of NHIPEC was identified as an independent predictor of PFS ( p < 0.0001). OS did not differ significantly between treatment groups ( p = 0.062), although a trend favouring NHIPEC was noted. Incidence of grade 3–4 adverse events and the surgical complexity score of IDS were similar between the two groups. Conclusions Compared with IV NACT alone, the combination of NHIPEC and IV NACT resulted in improved tumour response and longer PFS. The addition of NHIPEC did not increase the risk of adverse effects or affect the complexity of IDS.