Frequency of Epstein Barr Virus Positivity in Gastric Cancer and Adjacent Non-Tumoral Epithelium

Background Epstein-Barr virus –associated gastric cancer is one of four molecular subtypes defined by the Cancer Genome Atlas Program. Epstein-Barr virus –associated gastric cancer incidence has ethnic and geographical differences. The aims of the present study were to investigate the frequency of EBV in gastric cancer tissues and adjacent non-tumoral epithelium. Materials and Methods EBV positivity was assessed by chromogenic EBER-ISH in tumor tissues of 101 patients who were diagnosed with gastric carcinoma and underwent gastrectomy in our center between January 2008 and August 2023. The link between EBV incidence in gastric cancer, survival and clinicopathological prognostic factors was statistically assessed. Results EBV was positive in tumor tissue in 6 of 101 (%5,9) cases. In addition, positive staining was detected in intestinal metaplasia areas adjacent to the tumor in 10 cases (9.9%) and in normal gastric mucosa adjacent to the tumor in 13 cases (12.9%). All 6 cases with EBV- associated gastric cancer were male, 4 had diffuse histological type and 3 were histological grade 3, 4 had lymph node metastases and 2 had distant metastases. No statistically significant correlation was found between EBER positivity and clinicopathological prognostic factors, except for male gender (p= 0.021). There was no statistical correlation between EBV positivity and survival. Conclusion The frequency of EBV- associated gastric cancer was 5.9% in our center. EBV positivity is also present in inflammatory cells, intestinal metaplasia and normal tissues adjacent to gastric carcinoma tissue.