Genetic variants of EBI3, tumor Epstein-Barr virus, and human cytomegalovirus status in HPV-negative oral cancer

Abstract

Oral squamous cell carcinoma (OSCC), a malignancy with high recurrence rate and poor survival, may be influenced by immune-related genetic variations and oncogenic viruses. Objective  This study evaluated the clinical relevance of EBI3 polymorphisms, along with tumor Epstein–Barr virus (EBV) and Human Cytomegalovirus (HCMV) status, in prognostically adverse HPV-negative OSCCs. Methodology  EBI3 (rs4740, rs4905, rs428253) genotyping was performed by qPCR in 95 HPV-negative OSCC patients and 108 age- and sex-matched controls. Tumor HPV, EBV, and HCMV status were assessed by qPCR. EBV viral load was calculated by exponential approach and a relative estimate of EBV copies per 105 cells. Associations with overall survival (OS) and recurrence-free survival (RFS) were evaluated by Kaplan-Meier and Cox regression analyses. Results  EBV-positive tumors showed a significant association with increasing nodal stage (P=0.020). EBV viral load stratification (negative, low, high) presented a non-significant trend toward association with advanced tumor stage (P=0.060). Notably, EBI3 rs428253 predicted worse OS in EBV-positive patients, whereas rs4740 and rs4905 variants were associated with advanced tumor stage (P=0.024 and P=0.018). rs4740 and rs4905 variants were inversely associated with OSCC risk in dominant and overdominant models. Analysis detected HCMV in 7.4% of tumors but was not clinically relevant. Conclusions  EBI3 genetic variants and EBV status may have prognostic relevance in HPV-negative OSCC. EBV may interact with the host genetics to influence nodal metastases and outcomes, suggesting a potential EBV-EBI3 axis, which warrants further investigation. Future precision oncology approaches may incorporate host and viral genetic markers to identify and stratify high-risk HPV-negative OSCC patients