Survival of squamous cell carcinoma of the head and neck in relation to human papillomavirus infection: review and meta-analysis.

Human papillomavirus (HPV) has been associated with head and neck squamous cell carcinomas (HNSCC), especially of the oropharynx, with highest distribution in the tonsils. HPV infection has been associated with improved outcome, although not all the studies show consistent results. The reason for this is not clear. We reviewed all published articles and conducted a meta-analysis on the overall relationship between HPV infection and overall survival (OS) and disease-free survival (DFS) in HNSCC. Patients with HPV-positive HNSCC had a lower risk of dying (meta HR: 0.85, 95% CI: 0.7-1.0), and a lower risk of recurrence (meta HR: 0.62, 95%CI: 0.5-0.8) than HPV-negative HNSCC patients. Site-specific analyses show that patients with HPV-positive oropharyngeal tumours had a 28% reduced risk of death (meta HR: 0.72, 95%CI: 0.5-1.0) in comparison to patients with HPV-negative oropharyngeal tumours. Similar observations were made for DFS (meta HR: 0.51, 95% CI: 0.4-0.7). There was no difference in OS between HPV-positive and negative non-oropharyngeal patients. The observed improved OS and DFS for HPV-positive HNSCC patients is specific to the oropharynx; these tumours may have a distinct etiology from those tumours in non-oropharyngeal sites.