Significant association of PD-L1 expression with human papillomavirus positivity and its prognostic impact in oropharyngeal cancer

Abstract Background The programmed death pathway plays a role in persistent human papillomavirus (HPV) infection as well as in resistance to immune elimination during malignant progression. In this study, we examined PD-L1 expression by immunohistochemistry and tumour infiltrating lymphocytes (TIL) in 214 patients with oropharyngeal squamous cell cancer (OPSCC) to assess its clinical significance. Results HPV-positive OPSCC were significantly more likely to express PD-L1 than HPV-negative OPSCC (85.2% vs 57.1%, p  Conclusion Our findings suggested that different immune profiles in oropharyngeal cancer by HPV status and the effect of HPV on the outcomes is modified by PD-L1 expression.