Comprehensive analysis and clinical implication of PD-l1 expression considering HPV status in oropharyngeal squamous cell carcinoma

Abstract

Background/Aim: This study was conducted to comprehensively evaluate programmed cell death ligand 1 (PD-L1) expression, and analyze the clinical and prognostic implications of PD-L1 expression in oropharyngeal squamous cell carcinoma (OPSCC). Patients and Methods: We evaluated the expression of PD-L1 using the antibodies SP263 and SP142 in 106 patients with OPSCC, using immunohistochemistry. PD-L1 expression was subdivided into tumor cell score (TC), immune cell score (IC), and combined score (CS). Correlations between each PD-L1 expression and HPV status, clinicopathological features, and survival were analyzed. Results: The expression levels of PD-L1 SP263 and SP142 were significantly correlated. High PD-L1 SP263 TC and CS and SP142 IC and CS were associated with HPV positivity. PD-L1 expression showed no effect on survival in all patients' group. However, in the subgroup analysis, high TC and CS of both PD-L1 SP263 and SP142 were correlated with shorter time to recurrence in the HPV positive group. Conclusion: High expression of PD-L1 was associated with HPV positivity in OPSCC. In addition, high expression of PD-L1 might suggest a poorer outcome, especially in the HPV positive subgroup. PD-L1 could be a useful predictive and prognostic biomarker in OPSCC.