Nozomi Ito1, Hironori Tsujimoto2, Hiroyuki Horiguchi1, Hideyuki Shimazaki3, Hiromi Miyazaki4, Daizoh Saitoh4, Yoji Kishi1, Hideki Ueno1. 1. Department of Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan. 2. Department of Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan. Electronic address: tsujihi@ndmc.ac.jp. 3. Department of Pathology, National Defense Medical College, Tokorozawa, Saitama, Japan. 4. Division of Traumatology, National Defense Medical College Research Institute, Tokorozawa, Saitama, Japan.
Abstract
BACKGROUND: The aim of this study was to evaluate the association between the expression of programmed death ligand-1 (PD-L1) and clinical outcomes in patients with surgically resected esophageal squamous cell carcinoma (ESCC). MATERIALS AND METHODS: We included 76 patients with primary ESCC who underwent surgical resection between January 2009 and December 2014 at National Defense Medical College Hospital. Using the tumor tissues, we evaluated PD-L1 expression in tumor cells and stromal reactive lymphocytes via immunohistochemistry. Furthermore, the relationship between PD-L1 expression and the clinicopathological status of patients with ESCC was investigated. RESULTS: PD-L1 expression in tumor cells was detected in 39.5% of the patients. In addition, 51.3% of the patients had PD-L1-positive stromal reactive lymphocytes and exhibited significantly longer overall survival than those with lack of PD-L1 expression in stromal reactive lymphocytes (median survival time, 56.0 versus 27.3 mo; log-rank test, P = 0.04). Patients with lack of PD-L1 expression in both tumor cells and stromal reactive lymphocytes showed worse overall survival than those with the PD-L1-positive expression in tumor cells and/or stromal reactive lymphocytes (P = 0.02). CONCLUSIONS: PD-L1-positive expression in stromal reactive lymphocytes, rather than in tumor cells, is associated with a longer survival in patients with ESCC.
BACKGROUND: The aim of this study was to evaluate the association between the expression of programmed death ligand-1 (PD-L1) and clinical outcomes in patients with surgically resected esophageal squamous cell carcinoma (ESCC). MATERIALS AND METHODS: We included 76 patients with primary ESCC who underwent surgical resection between January 2009 and December 2014 at National Defense Medical College Hospital. Using the tumor tissues, we evaluated PD-L1 expression in tumor cells and stromal reactive lymphocytes via immunohistochemistry. Furthermore, the relationship between PD-L1 expression and the clinicopathological status of patients with ESCC was investigated. RESULTS:PD-L1 expression in tumor cells was detected in 39.5% of the patients. In addition, 51.3% of the patients had PD-L1-positive stromal reactive lymphocytes and exhibited significantly longer overall survival than those with lack of PD-L1 expression in stromal reactive lymphocytes (median survival time, 56.0 versus 27.3 mo; log-rank test, P = 0.04). Patients with lack of PD-L1 expression in both tumor cells and stromal reactive lymphocytes showed worse overall survival than those with the PD-L1-positive expression in tumor cells and/or stromal reactive lymphocytes (P = 0.02). CONCLUSIONS:PD-L1-positive expression in stromal reactive lymphocytes, rather than in tumor cells, is associated with a longer survival in patients with ESCC.