Noppadol LarbcharoensubKomkrit MahapromChuleeporn JiarpinitnunNarumol TrachuNattha TubthongPoompis PattaranutapornEkaphop SirachainanNuttapong NgamphaiboonFaculty of Medicine, Ramathibodi Hospital, Mahidol UniversityDivision of Medical OncologyDivision of Radiation Oncology2019-08-232019-08-232018-12-01American journal of clinical oncology. Vol.41, No.12 (2018), 1204-12101537453X2-s2.0-85054010987https://repository.li.mahidol.ac.th/handle/123456789/44973OBJECTIVES: Immunotherapies that target the programmed death-1/ programmed death-1 ligand (PD-1/PD-L1) immune checkpoint pathway have shown promise in nasopharyngeal carcinoma (NPC) in early phases clinical studies. Here, we evaluated PD-1 and PD-L1 expression and CD8+ tumor-infiltrating lymphocytes (TILs) in NPC patients. MATERIALS AND METHODS: Newly diagnosed NPC patients were identified through the institutional database between January 2007 and December 2012. PD-L1 and PD-1 expression, Epstein-Barr virus (EBV) status, and CD8+ TIL numbers were measured in archival tumor samples at diagnosis and their correlations with clinicopathologic features, including survival, were evaluated. RESULTS: A total of 114 NPC patients were analyzed. Most patients (96%) were EBV positive. PD-L1 was expressed in ≥1% of tumor cells (TCs) in 69% of patients, in ≥50% of TCs in 12% of patients, and in ≥5% of either TCs or infiltrating immune cells in 71% of patients. CD8+ TILs were present in tumors from all patients, whereas only 11% of tumors expressed PD-1. There were no correlations between PD-L1 expression and CD8+ TIL abundance, PD-1 expression, or survival. CONCLUSIONS: Approximately 70% of EBV-positive NPC expressed PD-L1, but this did not correlate with patient survival or clinicopathologic features. The findings of this study represent the immune biomarker profile of confirmed EBV-associated NPC in an endemic region. Since the current clinical development of immune checkpoint inhibitor for NPC is mostly focusing on an EBV-associated tumor, differences in immune biomarker profiles and EBV status of endemic and nonendemic regions should be further explored.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyMedicineArticleSCOPUS10.1097/COC.0000000000000449