Purpose

Patients will be registered prior to, during or at the completion of neoadjuvant chemotherapy (Paclitaxel 175 mg/m2 IV over 3 hours and Carboplatin AUC 6 IV on Day 1 every 21 days for 3-4 cycles). Registered patients who progress during neoadjuvant chemotherapy will not be eligible for iCRS and will be removed from the study. Following completion of neoadjuvant chemotherapy, interval cytoreductive surgery (iCRS) will be performed in the usual fashion in both arms. Patients will be randomized at the time of iCRS (iCRS must achieve no gross residual disease or no disease \>1.0 cm in largest diameter) to receive HIPEC or no HIPEC. Patients randomized to HIPEC (Arm A) will receive a single dose of cisplatin (100mg/m2 IP over 90 minutes at 42 C) as HIPEC. After postoperative recovery patients will receive standard post-operative platinum-based combination chemotherapy. Patients randomized to surgery only (Arm B) will receive postoperative standard chemotherapy after recovery from surgery. Both groups will receive an additional 2-3 cycles of platinum-based combination chemotherapy per institutional standard (Paclitaxel 175 mg/m2 IV over 3 hours and Carboplatin AUC 6 IV on Day 1 every 21 days for 2-3 cycles) for a maximum total of 6 cycles of chemotherapy (neoadjuvant plus post-operative cycles) followed by niraparib individualized dosing until progression or 36 months (if no evidence of disease).