Characterization of oral microbiota in HPV and non-HPV head and neck squamous cell carcinoma and its association with patient outcomes

Objective: To investigate the interplay among the oral microbiota, HPV infection, traditional risk factors and patient outcomes in head and neck squamous cell carcinoma (HNSCC). Materials and Methods: A multi-center study of HNSCC patients with paired tumor and control tissues. We characterized the oral microbiota and HPV infection of tissues in 166 Chinese adults by sequencing the bacterial 16S rRNA V3-V4 and HPV L1 regions, respectively, and examined the associations among the oral microbiota, HPV and clinical features. Results: A total of 15.7% of the surveyed HNSCC patients were positive for HPV DNA, with infection rates varying from 66.7% in oropharyngeal SCC to 10.4% in oral cavity SCC (OSCC). No HPV infection was detected in the surveyed hypopharyngeal SCC. HPV16 was largely the predominant type. HPV infection in non-OSCC, especially oropharyngeal SCC, was associated with advanced N stage and superior survival outcomes. Oral microbiota dysbiosis was observed in HNSCC tumors, with differentially abundant taxa mainly associated with HNSCC subtype, T stage, survival/relapse, HPV infection, and smoking. Notably, the enrichment of Fusobacterium in tumor tissues of OSCC patients was associated with no smoking, early T stage, early N stage, and better 3-year disease-specific survival. Conclusion: Our findings underscore the involvement of oral microbiota dysbiosis in OSCC pathogenesis, Fusobacterium is involved with improved OSCC patient outcomes, especially in patients lacking traditional risk factors. Understanding the complex interactions among the oral microbiota, HPV infection and other risk factors for HNSCC will provide important insights into the pathogenesis of HNSCC.