Feasibility of quantitative PCR-based saliva rinse screening of HPV for head and neck cancer

Human papilloma virus (HPV) 16 is likely to be an etiologic factor in a subset of head and neck squamous cell carcinomas (HNSC). We investigated the ability of a quantitative PCR-based assay to detect HPV 16 in salivary rinses as a screening method for HNSC. Real time quantitative PCR was applied to detect HPV16 E6 and E7 DNA level in 92 primary tumors and salivary rinses from patients with HNSC and 604 control subjects without HNSC. A total of 45.6% (42/92) of primary HNSC and 32.6% (30/92) of saliva rinse samples from HNSC patients had any detectable HPV 16 DNA, 30.4% (28/92) of tumors had HPV 16 levels >0.1 copies/cell. HPV16 was detected in 50% (confidence interval [CI] = 34.2-65.8%) (21/42) of the saliva rinse samples from HNSC patients with detectable HPV16 level in their tissue, 18% (CI = 8.4-30.9%) (9/50) of saliva rinse samples from patients with HPV 16 negative primary HNSC, in 2.8% (CI = 1.7-4.5%) (17/604) of the normal controls (p < 0.001). Using a cutoff of HPV 16 >0.001 copies/cell in saliva rinse yielded a sensitivity of 30.4% and a specificity of 98.3%. Nonsmokers had significant higher HPV 16 level than smokers in the cohort of cancer patients. HPV 16 DNA in saliva rinses can reflect HPV 16 status of primary HNSC. Quantitative analysis of HPV 16 DNA in salivary rinses allows for detection of HPV-related HNSC, however, specific limitations exist that prevent the application of this as a screening technique for a broad population.