627 The ‘paradigm-shift’ in advanced ovarian cancer: outcomes of extensive cytoreductive surgery. A single center retrospective analysis

Introduction/Background The standard surgical treatment of advanced ovarian carcinoma is primary debulking surgery (PDS) aiming to complete cytoreduction. The need to achieve complete cytoreductions has shifted the surgical paradigm to more complex procedures, including multiple bowel resections and upper abdomen procedures, whose impact on peri-operative morbidity is controversial. In this retrospective single-center analysis we aimed to explore the impact of extensive cytoreductive surgery on morbidity and oncologic outcomes. Methodology We retrieved clinico-pathological data of 137 patients with advanced non-mucinous high-grade ovarian carcinoma (HGOC) who received PDS at our institution from January 2015 to December 2020. Patients treated in 2015–2017 (Group1) were compared to patients treated in 2018–2020 (Group2). The two periods were chosen according to the higher complexity of surgical procedures introduced at our institution from 2018. Results A significant increase in complete and optimal cytoreduction was observed in Group2 (RD=0: 33% vs 61%, p=0,008; RDConclusion An extensive surgical effort with routine implementation of upper abdomen procedures leads to a significant increase in complete cytoreduction and is not burdened with increased morbidity. Arm-in-arm with novel maintenance therapies, it contributes to increase the outcomes of patients with advanced HGOC. Disclosures We have no disclosures.