Despite significant advancements in imaging technologies, surgical techniques, chemotherapeutic regimens, and treatment strategies in recent years, ovarian cancer continues to remain the most deadly gynecological malignancy. Approximately 90% of ovarian cancers originate from the coelomic epithelium or modified mesothelial cells and are classified as epithelial ovarian cancers. The majority of patients with epithelial ovarian cancer (70-80%) present in advanced stages. The primary treatment for advanced-stage (stage 3-4) disease consists of primary cytoreductive surgery followed by adjuvant chemotherapy. Cytoreductive surgery aims to remove all visible tumor implants regardless of the extent of the disease and achieve no visible residual tumor (complete cytoreduction, R0) at the end of the surgery. In cases where R0 cannot be achieved (due to poor general condition and/or extensive tumor that cannot be completely excised surgically), the option of neoadjuvant chemotherapy followed by interval cytoreductive surgery is considered. Primary cytoreductive surgery is still the preferred option and is considered a quality indicator for centers performing advanced-stage ovarian cancer surgeries. Despite advancements in surgery, the decision for interval surgery following primary surgery or neoadjuvant chemotherapy is often based on the surgeon's experience, imaging results, and clinic preferences. Various methods and scores have been published and applied to predict which patients are suitable for primary surgery. The Cukurova score developed in our clinic conceptualizes prioritizing surgical procedures using radiological imaging and diagnostic exploratory laparoscopy to achieve complete cytoreduction in harmony with the patient's clinical and performance status, rather than focusing solely on tumor burden. The score showed high success rates for complete cytoreduction and also was useful in terms of predicting the morbidity and mortality. However, the Cukurova score study was conducted in single center. Validation of scores in centers with different capacities is expected to facilitate their widespread use and acceptance. Therefore, in this study, the investigators plan to conduct a validation study of the score in a total of 20 centers in Turkey, including our center. This study aims to evaluate the validity of the Cukurova score in predicting outcomes of primary cytoreduction in advanced ovarian cancer patients and thus determining the decision for primary cytoreductive surgery or neoadjuvant chemotherapy followed by interval cytoreductive surgery.