Analysis of HPV-16 viral load, integration status, and p16 expression in relation to EBV co-infection and cervical lesion severity

Cervical cancer, one of the most common cancers in women, is primarily driven by high-risk human papillomaviruses (HPV) infections, particularly HPV-16. Co-infection with Epstein-Barr virus (EBV) has been reported to exacerbate disease progression by influencing HPV genome integration. This study examines HPV-16 integration status, p16INK4a expression, and their relationship with EBV co-infection and viral load in cervical cancer cases. In this study, 134 HPV-16-positive formalin-fixed, paraffin-embedded cervical samples were collected and analyzed for HPV-16 viral load, genome integration and EBV co-infection, followed by p16INK4a immunohistochemistry. Statistical analysis was performed to examine the association between viral markers and cervical cancer progression. HPV-16 viral loads varied significantly by histological grade, with the highest loads observed in cervical intraepithelial neoplasia 2 (CIN 2) lesions. HPV integration status revealed episomal forms in 32.8% of samples, mixed forms in 56%, and fully integrated forms in 11.2%. p16INK4a expression correlated with disease progression, increasing with CIN grade and in squamous cell carcinoma (SCC). EBV was detected in 13.4% of samples, but no significant associations were found between EBV infection and HPV integration, viral load, or p16INK4a expression levels. HPV-16 viral load and integration status are strongly associated with cervical lesion severity, while p16INK4a expression increases with lesion grade, indicating its utility as a diagnostic marker. EBV co-infection did not significantly impact lesion progression, suggesting that its role in cervical cancer remains unclear.