Systemic immune responses are associated with molecular characteristics of circulating tumor cells in head and neck squamous cell carcinoma.

Systemic immunity mediated by circulating immune cells may affect clinical features, as well as the characteristics of circulating tumor cells (CTCs) in patients with head and neck squamous cell carcinoma (HNSCC). The present study aimed to analyze the influence of circulating immune cells, using their markers, on clinical features to investigate the association between systemic immunity and the molecular characteristics of CTCs. Circulating immune-cell markers were associated with disease progression and clinical outcomes in patients with HNSCC. Meanwhile, there was no significant association between the presence of CTCs and systemic immune-related markers. Moreover, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit a expression in CTCs was significantly associated with higher lymphocyte counts (P=0.035) and an increased prognostic nutrition index (P=0.0157). Patients with CTCs expressing CD47 exhibited significantly higher neutrophil (P=0.0031) and monocyte (P=0.0016) counts. Patients with CTCs expressing programmed cell death 1 ligand 2 exhibited lower C-reactive protein (CRP) levels (P=0.0271) and a decreased CRP/albumin ratio (P=0.0207). The current results suggested that the interaction between CTCs and circulating immune cells may provide survival advantages via molecular alterations to CTCs.