SUROVA - Surgery in Ovarian Cancer, Comparing Primary and Interval Cytoreductive Surgery

Inclusion Criteria: * Patients \> 18 years old. * Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1 at the time of the surgery. * Invasive high-grade epithelial ovarian cancer, fallopian tube carcinoma, or primary peritoneal carcinoma in stage International Federation of Gynecology and Obstetrics (FIGO) IIIB-IVB (IVB only if resectable metastases are present), suspected or histologically confirmed and newly diagnosed. * Patient underwent primary surgery or first course of neoadjuvant chemotherapy between January 1, 2018, and December 31, 2019. * American Society of Anesthesiologists Physical Status Classification System (ASA) score 1 or 2 at the time of the surgery. * Surgery performed by laparotomy with an attempt of maximal effort. * The surgeon must be a certified or non-certified gynecologic oncologist. * Based on all available information before the surgery (primary or interval), the patient was considered completely resectable. * Adequate bone marrow function: Absolute neutrophil count (ANC) ≥ 1.5 x 109/L. * Preoperative imaging (either CT, whole-body MRI, or positron emission tomography (PET)-CT) excluding unresectable disease as per European Society of Gynaecological Oncology (ESGO) criteria. * Surgical report on residual disease after surgery. Exclusion Criteria: * Non-epithelial malignant ovarian neoplasms and borderline tumors. * Secondary invasive neoplasms in the last 5 years (except synchronal endometrial carcinoma FIGO IA G1/2, non melanoma sk…