Programmed death-ligand 1 and p53 as a biomarker in predicting oropharyngeal squamous cell carcinoma

Introduction. Currently, the pathogenetic role of the human papillomavirus (HPV) in carcinogenesis is well studied, that most cases of oropharyngeal squamous cell carcinoma are associated with the persistence of this infection. In addition to HPV infection, the involvement of programmed death-ligand 1 (PD-L1) and p53 proteins in the initiation and progression of oropharyngeal squamous cell carcinoma provides their formation as additional biomarkers in predicting the disease.

Aim. To study the prognostic role of PD-L1 and p53 expression in oropharyngeal squamous cell carcinoma depending on HPV status.

Materials and methods. The study included 62 patients with oropharyngeal squamous cell carcinoma T1–4N0–3M0 (Tumor, Nodus and Metastasis, (TNM), 7th edition) treated in 2015–2020 at the Republican Specialized Scientific and Practical Medical Center of Oncology and Radiology and in the Tashkent and Samarkand city branches. All patients underwent immunohistochemical analysis for the presence of p16INK4a, PD-L1 and p53 protein expression in formalin-fixed and paraffin-embedded tumor tissue samples.

Results. Based on the results of the assessment, it was found that positive HPV status, low and medium levels of PD-L1 expression and positive regulation of wild-type p53 are associated with favorable outcomes in patients with oropharyngeal squamous cell carcinoma. Negative HPV status, high and very high levels of PD-L1 expression, loss of wild type p53 function with upregulation of p53 mutant type leads to worse disease outcomes.

Conclusion. Thus, the assessment of the expression of the onco-suppressor protein p53 helps to determine the biology of cancer cells in patients with oropharyngeal squamous cell carcinoma and suggest sensitivity to ongoing therapy, and by studying the regulation of the PD-L1 protein, antitumor immune regulation can be suggested in these patients.