Immune cells and prognosis in HPV-associated oropharyngeal squamous cell carcinomas: Review of the literature

•First review on immunological features of HPV-associated oropharyngeal tumors.•Patient outcome is associated to a high number of CD8, a low CD4/CD8 ratio and CD98 positive cells, and possibly absence of HLA1.•CD4 and HLA2 are found insignificant in relation to patient outcome.

SummaryCurrently, oropharyngeal squamous cell carcinomas (OPSCC) are treated based on the traditional TNM-classification, although this scheme might be inadequate for the subgroup of human papillomavirus (HPV)-associated OPSCCs. It remains debatable whether this subgroup of patients with favorable prognosis should be offered altered treatment. Besides the well-known biomarkers of HPV and p16, new promising immune cells and markers might nuance the prognosis and treatment for patients with HPV+ OPSCC. We systematically reviewed the literature on immunological features of HPV-associated OPSCCs, and report that a high number of cytotoxic T cells (CD8s) and a low number of CD98 positive cells is associated with better outcome, while an increased CD4/CD8 ratio and a high human leukocyte antigen 1 (HLA1) intensity is most likely associated with worse outcome. These findings might contribute to future OPSCC staging and treatment.