The value of p16 and HPV DNA in non-tonsillar, non-base of tongue oropharyngeal cancer.

Background: Oropharyngeal squamous cell carcinoma (OPSCC) is dominated by tonsillar and tongue base carcinomas (TSCC/BOTSCC), but there are carcinomas at other sites, such as uvula/soft palate/pharyngeal wall here defined as other OPSCC. Human papillomavirus (HPV) positive TSCC/BOTSCC have favorable outcome, and the TNM-classification separates OPSCC into HPV mediated (p16 ^INK4a overexpressing, p16+) and HPV unrelated OPSCC (p16 ^INK4a non-overexpressing, p16-) cancer, but the prognostic role of p16+ in other OPSCC is unclear.
Aims/objectives: This study therefore aimed to further investigate the prognostic role of p16+, presence of HPV DNA, or both combined in other OPSCC.
Material and Methods: 195 other OPSCC, from patients diagnosed 2000-2018 were tested for p16, and/or presence of HPV DNA and the data correlated to outcome.
Results: Neither overall survival, nor disease free survival correlated to presence of p16+ or HPV DNA in other OPSCC. p16+ and HPV DNA presence were correlated ( p  < .0001), but the sensitivity of p16 as a surrogate marker for presence of HPV DNA was low (49%).
Conclusions and Significance: The data suggest that p16+ (and p16+/HPV DNA) positive other OPSCC should be analyzed cautiously and possibly separately from the HPV mediated OPSCC staging group.