Molecular detection of Epstein-Barr virus in paraffin-embedded tissue samples of patients suffering gastric cancer in Ahvaz, Iran: a case-control study.

Background and objectives: Gastric cancer (GC) is the third most common cause of cancer-related mortality. Epstein-Barr virus (EBV) is associated with several human tumors. The present research was performed to investigate the prevalence of EBV-associated gastric cancer (EBVaGC) among Iranian patients.

Materials and methods: Seventy cases of gastric cancer and 30 cases of gastric ulcer, all preserved in formalin-fixed paraffin-embedded (FFPE), were examined in a case-control study conducted between 2011 and 2018. The specimens underwent analysis to detect the presence of the EBV genome using a Nested-PCR method targeting EBNA1. Subsequently, samples testing positive for the EBNA1 underwent further testing for the presence of the EBER gene using PCR. Finally, Positive samples were subjected to sequencing.

Results: Five out of 70 cases (7%) were found to be positive for EBV based on EBNA1 testing, while all EBNA1 positive samples were negative for EBER. Notably, EBV was not detected in patients with gastric ulcer. The mean age of EBV-positive gastric carcinomas pateints was 64.5 years. Within this group, 60% were male and 40% were female. A higher prevalence of EBV association was observed in diffuse-type cases, with 60% (3 out of 24) testing positive, compared to intestinal-type cases where 40% (2 out of 46) were EBV-positive. Most cases of EBVaGC belonged to grade Ⅰ.

Conclusion: This research demonstrates a low prevalence of EBVaGC in Iran. Discrepancies in EBVaGC occurrence among countries could be attributed to epidemiological variables and dietary practices. A comprehensive studies will provide significant contributions to understanding of its etiology.