Human papillomavirus and oropharyngeal squamous cell carcinoma: a New Zealand cohort study

Background Human papillomavirus (HPV)‐related oropharyngeal squamous cell carcinomas (OPSCC) are clinically, epidemiologically and prognostically distinct from other OPSCCs. The incidence of HPV‐related OPSCCs has increased significantly worldwide over the past few decades. However, no studies of OPSCC with direct molecular HPV testing has been conducted in New Zealand. Aims To estimate the proportion of OPSCCs attributable to HPV infections in a New Zealand population with a validated HPV testing algorithm. Methods HPV‐status was determined by p16 immunohistochemistry and polymerase chain reaction (PCR) of both L1 and E6/7 genes on 55 OPSCCs diagnosed in 2010 and 2011 in Central and South Auckland. Baseline and survival analyses were performed according to HPV status. Results Forty‐one (75%) of OPSCC tumours had HPV infections. There was 98% concordance between p16 immunohistochemistry and real‐time E6/E7 PCR. After a median follow‐up period of 2.6 years, patients with OPSCC of HPV aetiology had more favourable outcomes compared to patients with HPV‐negative OPSCC (hazard ratio 0.14, P = 0.02) after adjustment for other variables. Conclusion This study highlights the significant role that HPV plays in the aetiology of OPSCC in New Zealand, and confirms the high rate of accuracy of p16 immunostaining.