Association of Epstein-Barr Virus and its clinical relevance in Human Papillomavirus-negative oral squamous cell carcinoma: A cohort study from South India

Objective: The study assessed the prevalence and clinical implications of Epstein Barr Virus (EBV)-positive but Human Papillomavirus (HPV)-negative oral squamous cell carcinoma (OSCC) in a tertiary care hospital setting. The overall goal was to elucidate the potential impact of EBV on OSCC disease progression and prognosis. Design: A total of 134 surgically resected and histopathologically confirmed OSCC tumor biopsies were collected from a tertiary care hospital. Tumor samples were analyzed for HPV and EBV using conventional and nested PCR. Clinical and demographic data, including age, sex, risk factors, tumor stage, and survival outcomes, were collected and analyzed to assess associations between EBV status and disease characteristics. Results: All the tumor samples tested negative for HPV. However, EBV was detected in 74 cases (55.3 %) using nested PCR which was confirmed by sanger sequencing. EBV prevalence was higher in males (62.1 %), and the left buccal mucosa was the most affected site, accounting for 34 % of cases. Although statistically not significant, 63.5 % (n = 47) of the EBV positive subjects had a history of consuming both tobacco and alcohol. Of these 20 subjects showing recurrence, 35 % (n = 7) were EBV positive suggesting poor prognosis for EBV positive OSCC subjects. Conclusion: This study highlights a significant prevalence of EBV in HPV-negative OSCC cases, suggesting a potential oncogenic role for EBV in OSCC progression, particularly in patients with established lifestyle risk factors. These findings underscore the need for further research into EBV's molecular mechanisms in OSCC and its utility as a biomarker for prognosis and therapeutic targeting. The results advocate for region-specific strategies to better understand and manage EBV-associated OSCC, offering potential pathways to improve outcomes in high-risk populations.