Study on the molecular pathogenesis of human papillomavirus (HPV)-related squamous cell carcinoma of the tongue-base region and tonsil

We investigated the prevalence of high-risk human papillomavirus (HR-HPV) in squamous cell carcinoma of the tonsil and tongue-base region, and evaluated its clinical features and prognostic implications according to HPV status and p16 and p53 expression. HR-HPV was positive in 16 (53%) of 30 samples. Of these positive cases, 15 (94%) carried HPV 16 sequences and only 1 (6%) carried a HPV58 sequence. Among the HPV-positive patients, the frequency of heavy smokers and drinkers was significantly lower than among the HPV-negative patients. Among the 30 patients, p16 was overexpressed in 16 (53%), and this overexpression was strongly associated with the presence of HR-HPV (P < 0.0001). In contrast, HPV-negative patients were more likely to have p53 overexpression (75%). On univariate analysis, both HPV-positive status (86% vs. 48%; P = 0.029) and p16 overexpression (100% vs. 31%; P < 0.001) significantly improved the overall survival (OS), respectively. On the other hand, p53 overexpression was significantly associated with inferior OS (42% vs. 83%; P = 0.004). These results indicate that it will be necessary to use these HPV-related biomarkers for decisions on staging and therapeutic strategy.