B-cell infiltration is associated with survival outcomes following programmed cell death protein 1 inhibition in head and neck squamous cell carcinoma

•PD-1/PD-L1 axis inhibitors have become the standard of care for recurrent/metastatic head and neck cancer (R/M HNSCC).•Low response rates dictate the need to identify resistance mechanisms and develop biomarkers for patient selection.•The associations of immune-cell density with treatment outcomes were investigated in nivolumab-treated R/M HNSCC cases.•Increased B-cell infiltration led to prolonged progression- free survival and improved PD-L1-based patient selection.•The synchronous assessment of B-cell infiltration and PD-L1 expression could guide therapeutic decisions in R/M HNSCC.