Advances in testing for human papillomavirus -mediated head and neck cancer.

Abstract

New evidence has recently emerged regarding the utility and benefits of dual p16 INKa (p16) and Human papillomavirus (HPV) status testing when determining the diagnosis and prognosis of patients with oropharyngeal cancer. HPV RNA polymerase chain reaction (PCR) is the most accurate diagnostic test. The other assays (HPV DNA PCR, HPV DNA/RNA in-situ hybridization (ISH) and p16) applied to formalin fixed tumour tissue have varying but high sensitivities and specificities. Dual p16 and HPV testing identifies discordant (p16+/HPV- or p16-/HPV+) results in 9.2% of cases, who have significantly poorer prognoses than p16+/HPV+, particularly in smokers. The proportion of discordant cases varies by region, and appears to be highest in regions with lowest attributable (p16+/HPV+) fractions. Dual testing improves prognostication for oropharyngeal cancer cases by identifying discordant cases and improving the prognostic power of the Tumour Node Metastasis (TNM) classification, especially in regions with high discordant rates. Dual testing is essential when considering patients for clinical trials of treatment de-escalation, and may be important when counselling patients on prognosis, especially in regions with high discordant rates and in smokers.