RESUMEN
The paper presents the results of the studies of gastric cancer (GC) associated with Epstein-Barr virus (EBV) among the patients residing in 4 geographical regions. In situ hybridization (ISH) techniques revealed that 49(11.4%) of the 430 examinees were EBV positive (EBV+), the virus-specific marker mRNA-1 of EBV, EBER-1) was found to be present in 80-100) of tumor cells. The proportion of EBV(+)-associated GC cases in different geographic regions ranged from 7.3 to 15%. These tumors were predominant in males (15%) as opposite to females (5.5%). Histological types most common among EBV+ tumors and their location in the stomach are also described. Serological findings indicated that the increased anti-EDV antibody response in 70% of GC cases coincided with the presence of the viral genetic information detected by ISH. In contrast to a humoral response to EBV, a humoral response to Helicobacter pylori was equal both in patients with EBV(+)- and EBV(-)-associated gastric tumors. Further molecular biological analysis of EBV isolates from virus positive and virus negative GC may answer the question whether there are really the so-called tumor and non-tumor variants of EBV.
