Immune related proteins and tumor infiltrating CD8+ lymphocytes in hypopharyngeal cancer in relation to human papillomavirus (HPV) and clinical outcome

Background Hypopharyngeal cancer (HPSCC) shows a poor clinical outcome, while HPSCC, caused by human papillomavirus (HPV), presents a better outcome. Here, HPCC, immune proteins, and tumor infiltrating CD8+ lymphocytes (CD8+ TILs) were evaluated in relation to HPV and outcome. Methods Fresh frozen tissue from four HPV‐positive HPSCC, 39 HPV‐negative HPSCC, and normal samples were analyzed for protein expression by the Proseek immuno‐oncology immunoassay. CD8+ TIL numbers evaluated by immunohistochemistry on 144 formalin‐fixed biopsies were analyzed in relation to clinical outcome. Results Proteins differing between HPV‐positive and negative HPSCC included CD8A, PD‐L1, Fas ligand, and chemokines. High CD8+ TIL numbers were correlated to improve clinical outcome in HPV‐negative HPSCC. Conclusions High expression of immune proteins in HPV‐positive HPSCC may explain the better clinical outcome. CD8+ TILs are of relevance for outcome of HPV‐negative HPSCC, while tumors with high immune activity but poor patient survival suggest a role for immune therapy.