Evaluation of systemic and local immune responses in patients with endometrial cancer.

Abstract

5594 Background: Several studies suggest that systemic immune response (SIR) and local immune response (LIR) have independent roles in multiple types of cancer. In endometrial cancer (EC), the correlation between SIR and LIR and its prognostic value remains unclear. Methods: A total of 146 EC patients (stage I-IV) who had undergone surgery from 2009 to 2015, were identified from a prospective institutional database. Lymphocyte/monocyte ratio (LMR) to represent SIR was calculated from preoperative blood samples. The presence of intratumoral and peritumoral infiltrating lymphocytes (TILs) on hematoxylin and eosin-stained slides was considered as a surrogate of LIR. LMR and TILs were correlated to pathological findings and survival outcomes (overall survival: OS, disease free survival: DFS). Results: A LMR cutoff value of 4.4 for survival was determined based on receiver operating characteristic (ROC) curve analysis. LMR high was significantly associated with endometrioid histology (p=0.03), lower grade (G1-2; p=0.003), < 50% myometrial invasion (p=0.01) and I-II stage (p=0.02). TILs were correlated with MSI-high (p<0.005), but not with LMR (p=0.3). Low LMR was associated with worse 5-year OS rates (64.5% vs 93.9%; p<0.01) and presence of TILs with better 5-years OS rates (72% vs 27%; p=0.04). On multivariate analysis (table 1) LMR, histology, stage and grade remained independent prognostic factors for OS (p=0.01). Using the combination of LMR and TILs, four groups with decreasing 5-years OS rates were identified: LMR-high/TILs+ (100%) > LMR-high/no-TILs (87%) > LMR-low/TILs+ (71%) > LMR-low/no-TILs (61%). Conclusions: In our series of resected EC patients, SIR (defined by LMR) constituted an independent prognostic factor for OS and LIR for DFS. We did not find any correlation between SIR and LIR, but the combination of both higher SIR and LIR showed better OS. [Table: see text]