RT Journal Article SR Electronic T1 PR042/#442  Survival benefit of cytoreductive surgery in patients with primary stage IV endometrial cancer: a systematic review & meta-analysis JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A53 OP A53 DO 10.1136/ijgc-2023-IGCS.84 VO 33 IS Suppl 4 A1 Pham, Eveline A1 Horeweg, Nanda A1 Marel, Jacolien Van Der A1 Nooij, Linda YR 2023 UL http://ijgc.bmj.com/content/33/Suppl_4/A53.1.abstract AB Introduction The role of cytoreductive surgery (CRS) in primary stage IV endometrial cancer (EC) remains debatable due to lack of evidence from large studies and heterogeneity of stage IV EC. To address this, we conducted a systematic review and meta-analysis to investigate the survival benefit of CRS in patients with primary stage IV EC.Methods Five medical literature databases were systematically searched for original studies reporting survival data on primary stage IV EC by outcome of CRS (complete, optimal, or incomplete resection). Pooled hazard ratio’s (HR) were calculated using a random-effects model.Results Twelve studies, including 733 patients, were analysed. Of them, 187 (26%) had complete CRS and 146 patients (20%) optimal CRS. In five studies, including 79 patients (11%), complete and optimal CRS were combined. Ten studies reported a significant overall survival (OS) benefit after complete (18–48 months), and optimal CRS (13–34 months) compared to incomplete CRS (7–19 months). In patients with serous EC or extra-abdominal metastasis, a benefit of complete/optimal CRS was also observed. The pooled data showed improved OS from complete/optimal vs. incomplete CRS (HR=0.38, 95% CI 0.21–0.69, p=0.0016) (figure 1). Heterogeneity between studies was substantial.Conclusion/Implications This study indicates an OS benefit of complete/optimal CRS for patients with primary stage IV EC, including patients with serous EC or extra-abdominal metastasis. A superior survival benefit was seen after complete CRS compared to optimal CRS. Despite the considerable heterogeneity between studies, our findings suggest that CRS should be considered in the treatment of patients with primary stage IV EC.Abstract PR042/#442 Figure 1 Forest plot of the meta-analysis comparing complete and optimal CRS vs incomplete CRS The p-value are the values mentioned by the authors