Increased PD-L1 and p16 Expression are Common in Oropharyngeal Squamous Cell Carcinoma

Abstract

Overexpression of p16 is closely related to human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (SCC) and pertains a prognostic relevance. Programmed cell death 1-ligand 1 (PD-L1) is another important marker, as anti-PD-L1 immunotherapy is available. Retrospective analysis of 57 cases of the SCC involving oropharynx (27 cases), hypopharynx (5 cases), larynx (11 cases), and oral cavity (14 cases) was performed. Each case was scrutinized for the basaloid morphology, p16, and PD-L1 expression. Basaloid morphology was identified in 47% of total cases. The majority of basaloid SCC variants were located in the oropharynx (89%). High expression of p16 was mostly observed in the oropharynx. High PD-L1 expression was seen predominantly in oropharyngeal and hypopharyngeal locations. Further studies in a larger cohort are necessary to correlate PD-L1 and p16 expression with survival.

PD-L1 Expression and Its Association With p16 in Head and Neck Squamous Cell Carcinoma in Southwestern Uganda

“…Our findings are in accordance with reports from China, 14,17,19 United States, 20 Italy. 21 In the present study, the positivity rate of PD-L1 positive HNSCC (70.37%) was significantly higher than that of their HPV-negative counterparts (24.64%).…”

Expression of PD-L1 is HPV/P16-independent in oral squamous cell carcinoma

“…However, the present study showed no association between p16 and PD-L1 expression in patients with OSCC. Again, previous studies have shown positive association [ 63 , 67 , 68 ] and no association between p16 and PD-L1 expression [ 43 , 69 ]. Collectively, these conflicting findings may indicate that high-risk HPV may be an alternative mechanism to induce PD-L1 expression in OSCC.…”