PD‐1 and PD‐L1 in locoregionally advanced nasopharyngeal carcinoma: Substudy of a randomized phase III trial.

Background: To evaluate the expression of programmed death‐1 (PD‐1) and programmed death‐ligand 1 (PD‐L1) by using immunohistochemistry analysis in locoregionally advanced nasopharyngeal carcinoma (NPC) patients receiving cisplatin, fluorouracil, and docetaxel followed by concurrent chemoradiotherapy. Methods: As part of a previously reported trial, 108 patients were enrolled in this study. Results: We observed that Epstein–Barr Virus (EBV) antibody levels were associated with PD‐1 positive staining in NPC and PD‐1 positive staining was identified as an independent prognostic factor for progression‐free survival (hazard ratio 0.363, 95% confidence interval 0.134‐0.987, P = .047). By contrast, the correlation between the PD‐L1 level and hemoglobin, lactate dehydrogenase and high‐sensitivity C‐reactive protein was not identified. Moreover, high levels of PD‐L1 staining were not significantly associated with clinical outcomes. Conclusion: NPC patients with negative PD‐1 staining had a significantly reduced survival outcome. Furthermore, patients with positive PD‐1 staining had significantly higher EBV antibody levels. [ABSTRACT FROM AUTHOR]