Increased Prevalence of EBV Infection in Nasopharyngeal Carcinoma Patients: A Six-Year Cross-Sectional Study

Simple Summary Epstein Barr Virus (EBV) is associated with at least 1% of global cancers including nasopharyngeal carcinoma (NPC). Studies on the molecular epidemiology of EBV should improve the understanding of NPC prognosis. Retrospectively, we collected demographic and clinical data for 146 NPC patients over a 6-year period between 2015 and 2020. We found a high prevalence of 96% of EBV infection in NPC patients with a predominance of genotype I detected in 73% of NPC samples. Although NPC had metastasized to 16% of body sites, it was not associated with EBV infection, except for lungs. Three-quarters of NPC patients were in the advanced stages of cancer and the overall survival (OS) mean time was 5.59 years. We found an increased prevalence of EBV infection in NPC patients higher than previously thought with a predominance of EBV genotype I. A future multi-center study with a larger sample size is needed to assess the true burden of EBV-associated NPC. Epstein Barr Virus (EBV) is implicated in the carcinogenesis of nasopharyngeal carcinoma (NPC) and currently associated with at least 1% of global cancers. The differential prognosis analysis of NPC in EBV genotypes remains to be elucidated. Medical, radiological, pathological, and laboratory reports of 146 NPC patients were collected retrospectively over a 6-year period between 2015 and 2020. From the pathology archives, DNA was extracted from tumor blocks and used for EBV nuclear antigen 3C (EBNA-3C) genotyping by nested polymerase chain reaction (PCR). We found a high prevalence of 96% of EBV infection in NPC patients with a predominance of genotype I detected in 73% of NPC samples. Histopathological examination showed that most of the NPC patients were in the advanced stages of cancer: stage III (38.4%) or stage IV-B (37.7%). Only keratinized squamous cell carcinoma was significantly higher in EBV negative NPC patients compared with those who were EBV positive (OR = 0.01, 95%CI = (0.004-0.32; p = 0.009)), whereas the majority of patients (91.8%) had undifferentiated, non-keratinizing squamous cell carcinoma, followed by differentiated, non-keratinizing squamous cell carcinoma (7.5%). Although NPC had metastasized to 16% of other body sites, it was not associated with EBV infection, except for lung metastasis. A statistically significant reverse association was observed between EBV infection and lung metastasis (OR = 0.07, 95%CI = (0.01-0.51; p = 0.008)). Although 13% of NPC patients died, the overall survival (OS) mean time was 5.59 years. Given the high prevalence of EBV-associated NPC in our population, Saudi could be considered as an area with a high incidence of EBV-associated NPC with a predominance of EBV genotype I. A future multi-center study with a larger sample size is needed to assess the true burden of EBV-associated NPC in Saudi Arabia.

Automated summary

This study retrospectively collected demographic and clinical data of 146 nasopharyngeal carcinoma (NPC) patients and found a high prevalence (96%) of Epstein Barr Virus (EBV) infection, with genotype I being the most common. EBV infection was associated with lung metastasis but not with metastasis to other sites. The majority of patients were in advanced stages of cancer, and the overall survival mean time was 5.59 years. Further multi-center studies with larger sample sizes are needed to assess the true burden of EBV-associated NPC.