Introduction/Background Ovarian cancer (OC) is the leading cause of death among women diagnosed with gynaecological cancer. The natural course of the disease is progression to peritoneal metastases (PM), a high rate of platinum chemoresistance, and a low overall survival rate, with no effect of a screening system. This background explains the interest in locoregional treatment of peritoneal disease which has shown a benefit in terms of overall and progression-free survival for selected patients treated with complete cytoreductive surgery. This pilot study aimed to investigate the feasibility and safety of secondary complete cytoreductive surgery after a bidirectional treatment of Pressurized IntraPeritoneal Chemotherapy (PIPAC) and systemic chemotherapy.

Methodology A retrospective single-tertiary-canter pilot study with unresectable stage III serous ovarian cancer patients treated by induction chemotherapy based on carboplatin and paclitaxel combined with a minimum of 3 PIPAC, between May 01, 2019 and October 30, 2021. All patients had a diagnostic laparoscopic exploration. After 3 cycles of chemotherapy PIPAC was initiated if unresectable disease without extraperitoneal metastases including loco-regional lymphadenopathy. Resectable disease after 3 cycles of bidirectional treatment was eligible for CRS. Hyperthermic IntraPeritoneal Chemotherapy (HIPEC) was done after complete CRS without the residual disease.

Results All patients completed at least 3 PIPAC (n=7, 89%) in a bidirectional approach, and one patient had completed 4 PIPAC. Most patients (n=6, 75%) were secondarily treated by CRS-HIPEC. In two patients the disease remained unresectable and had to be changed for second-line chemotherapy. Median PCI during surgery was 17 (IQR 2.3). The postoperative course was uneventful regarding severe complications.

Conclusion PIPAC is safe and feasible in a neo-adjuvant intent for unresectable ovarian cancer patients and may lead to complete CRS.