PDCD1 and head and neck squamous cell carcinoma: However, there were still some controversies for the combination of chemoradiotherapy and immunotherapy, such as timing, radiation dose, fractionation, and et al. In our study, the synergy of concurrent chemoradiotherapy with PD-1 inhibitor showed a promising results for the R/M HNSCC patients, with improved objective response rate (ORR) (70.0%, 95% CI 55.8% to 84.2%) and disease control rate (DCR) (100%, 95% CI 100% to 100%).