Abstract B34: The impact of lymphocyte-to-monocyte ratio (LMR) in patients with borderline resectable pancreatic head cancer after curative surgery

Introduction: The outcome of patients with borderline resectable pancreatic ductal adenocarcinoma (BR PDAC) remains dismal even if the patients received neoadjuvant chemotherapy followed by radical resection. Pancreatic resection is highly invasive and sometimes fatal; thus, useful preoperative indicators for favorable prognosis of patients with PDAC are needed. Lymphocyte-to-monocyte ratio (LMR) is a systemic inflammatory response marker associated with cancer outcome. In the present study, we evaluated the clinical significance of LMR for BR head-PDAC patients. Materials and Methods: Consecutive 67 borderline resectable (BR) head-PDAC patients who underwent pancreaticoduodenectomy from Jan. 2008 to Dec. 2017 at Chiba University Hospital were analyzed retrospectively. The levels of LMR were calculated by simply dividing the absolute lymphocyte count by the monocyte count from routine preoperative blood sample, and the cut-off value of LMR was determined by receiver operating curve analysis. All the participants were divided into two groups (High/Low) based on the level of LMR. Among the clinicopathologic factors, we analyzed the clinical significance of preoperative LMR using the Kaplan-Meier analysis and Cox proportional regression model. Results: The characteristics of participants were as follows: median age: 67 (interquartile range (IQR) 61-72) years old, sex M/F: 49/18, resectability based on NCCN 2018.2 (BR-PV/BR-A): 38/29, neoadjuvant chemotherapy (done/none): 36/31, adjuvant chemotherapy (done/none): 59/8, R0/1 resection: 51/16, respectively. The median level of preoperative LMR was 4.17 (IQR 2.51-6.09). The cut-off value of LMR was calculated to be 5.63 by applying Youden Index. All PDAC patients were classified into high LMR group (n=20) and low LMR group (n=47). The Kaplan-Meier analysis showed that the outcome of patients in high LMR group was significantly better compared to that in low LMR group (P=0.029 log-rank test). The median overall survival time after surgery was 17.6 months in low LMR group versus 38.1 months in high LMR group. Furthermore, multivariate analysis revealed that high LMR (P=0.012) and low preoperative CA19-9 level (P=0.012) were identified as independent prognostic factors of favorable outcomes in patients with BR head-PDAC. Conclusions: The present study demonstrated both LMR and preoperative CA19-9 were independent prognostic factors in patients with BR head-PDAC. Because these markers can be obtained preoperatively, they will contribute to determination of the strategy for treatment of BR PDAC patients. Citation Format: Yoji Miyahara, Shigetsugu Takano, Hideyuki Yoshitomi, Shingo Kagawa, Katsunori Furukawa, Tsukasa Takayashiki, Satoshi Kuboki, Daisuke Suzuki, Nozomu Sakai, Takashi Mishima, Eri Nakadai, Masayuki Ohtsuka. The impact of lymphocyte-to-monocyte ratio (LMR) in patients with borderline resectable pancreatic head cancer after curative surgery [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B34.