HPV16 status might correlate to increasing tumor-infiltrating lymphocytes in hypopharyngeal cancer.

Background: Human papillomavirus (HPV) plays a major etiological role in the increasing number of patients with head and neck squamous cell carcinoma (HNSCC).

Objectives: This study aimed at exploring the relationship between HPV infection and prognosis in patients with hypopharyngeal carcinoma (HPSCC).

Methods: We retrospectively analyzed 108 consecutive patients diagnosed with HPSCC from 2015 to 2018. Real-time fluorescent quantitative PCR and P16 immunohistochemistry were used to detect HPV infection in tissues of patients with hypopharyngeal carcinoma. The numbers of CD8, CD4 and Foxp3 cells in tumor parenchyma were obtained by immunohistochemical counting. Finally, the analysis was performed according to the clinicopathological variables and prognosis of the patients.

Results: Among 108 patients with HPSCC, 18 cases were detected by qPCR, and 16 subtypes accounted for the majority (77.8%). Kaplan-Meier analysis showed that HPV16+, higher CD8+, higher CD4+ and higher FoxP3+ TIL infiltration was strongly associated with superior three-year disease-free survival (DFS), cancer-specific survival (CSS) and overall survival (OS). Univariate analysis showed that HPV and CD4+ TIL had higher predictive value for prognosis.

Conclusions: HPV16 infection is significantly related to tumor immune infiltrating cells (TILs).