The aim of CHRONO trial is to compare the DFS when surgery is performed after 3 courses of NACT, or after 6 courses of NACT, in a prospective multi institutional randomized setting,considering only patients initially unsuitable for primary surgery.

Inclusion Criteria:

1. Female patients ≥18 years.

2. Histologically confirmed epithelial ovarian cancer, fallopian tube carcinoma or primary peritoneal carcinoma, high grade serous or endometrioïd, with the exception of mucinous, clear cell and carcinosarcoma histologies.

3. Performance status < 2 (see Appendix 2).

4. Documented International Federation of Gynecologic Oncology (FIGO 2014, Appendix 1) stage IIIB-IIIC-IVa unsuitable for complete primary cytoreductive surgery (confirmed by open laparoscopy or by laparotomy [not mandatory for stage IVA]).

5. Patient must be judged resectable after 3 courses of Neoadjuvant chemotherapy

6. Adequate bone marrow, liver and renal function to receive chemotherapy and subsequently to undergo surgery:

   • White blood cells (WBC) >3x109/L, absolute neutrophil count (ANC) ≥1,5x109/L, platelets (PLT)

     ≥100x109/L, hemoglobin (Hb) ≥9 g/dL,

   • Serum creatinine <1.25 x upper normal limit (UNL) or creatinine clearance ≥ 30 mL/min according to Cockroft-Gault formula or to local lab measurement, serum bilirubin <1.25 x UNL, AST(SGOT) and ALT(SGPT) <2.5 x UNL.

7. Signed informed consent obtained prior to any study-specific procedures.

8. Patient affiliated to, or a beneficiary of, a social security category

Exclusion Criteria:

1. Mucinous, clear cell , carcinosarcoma and low grade serous carcinomahistologies.
2. Synchronous or previous other malignancies within 3 years prior to starting study treatment, with the exception of adequately treated non-melanomatous skin cancer or carcinoma in situ (of the cervix or breast or other sites).
3. Patients with brain metastases, seizure not controlled with standard medical therapy, or history of cerebrovascular accident (CVA, stroke) or transient ischemic attack (TIA) or subarachnoid hemorrhage before 6 months from the enrollment on this study.
4. Any other concurrent medical conditions contraindicating surgery or chemotherapy that could compromise the adherence to the protocol (including but not limited to impaired cardiac function or clinically significant cardiac diseases, active or uncontrolled infections, HIV-positive patients on antiretroviral therapy, uncontrolled diabetes, cirrhosis, chronic active or persistent hepatitis, impaired respiratory function requiring oxygen-dependence, serious psychiatric disorders).
5. Pregnant or breastfeeding women.