Improved survival of Japanese patients with human papillomavirus-positive oropharyngeal squamous cell carcinoma

The prevalence of oropharyngeal carcinoma is rising in western Europe and the United States, where there appears to be a strong association between human papillomavirus (HPV) and oropharyngeal squamous cell carcinoma (OPSCC). However, such a correlation has not yet been fully evaluated in Japan. We performed a retrospective analysis of the association between tumour HPV status and the demographic and clinicopathological parameters of 71 patients with OPSCC at Hokkaido University Hospital, Japan, between 1998 and 2009. The parameters included age, gender, survival, tumour subsite, tumour-node-metastasis (TNM) stage, smoking history, second primary tumour status, recurrence/residual disease at the primary site, and overall survival. HPV status was established by multiplex polymerase chain reaction (PCR) analysis. Of the 71 oropharyngeal cancers, 20 were positive for HPV-16, two for HPV-18, and one for HPV-58. Kaplan-Meier survival analysis showed improved overall survival rates in patients with HPV-positive tumours (p = 0.0038) compared with HPV-negative tumours. Of the 45 patients who received chemoradiotherapy, HPV-positive patients experienced better overall survival than HPV-negative patients (p = 0.0032). In a multivariate analysis, the survival benefit of HPV-positive patients was independent of age and T and N classification. HPV status is a significantly favourable prognostic factor in oropharyngeal cancer and could be used as a marker to optimize the treatment of patients with this type of cancer in Japan.