Epstein-Barr virus genome polymorphisms of Epstein-Barr virus-associated gastric carcinoma in gastric remnant carcinoma in Guangzhou, southern China, an endemic area of nasopharyngeal carcinoma

Abstract

Epstein-Barr virus (EBV) is associated with a subset of gastric carcinoma which was defined as EBV-associated gastric carcinoma (EBVaGC). The proportion of EBVaGC in gastric remnant carcinoma (GRC) was apparently higher than that in conventional gastric carcinoma (CGC) which occurs in the intact stomach. To clarify the possible mechanisms, 26 GRC cases from Guangzhou were investigated for the presence of EBV, and the EBV genome polymorphisms of EBVaGC in GRC were analyzed. Besides, the clinicopathologic characteristics, EBV latency pattern of EBVaGC in GRC were also investigated. Eight (30.8%) out of 26 cases were identified as EBVaGCs. Type A strain, prototype F, type I, mut-W1/I1, XhoI− and del-LMP1 variants were predominant among EBVaGC patients, accounting for 7 (87.5%), 7 (87.5%), 8 (100%), 6 (75%), 5 (62.5%) and 8 (100%) cases, respectively. All EBVaGC cases were male and with the histology of diffuse-type carcinoma. The tumor cells expressed EBNA1 (87.5%) and LMP2A (62.5%) but not LMP1, EBNA2 and ZEBRA. Thus, the EBV latency pattern was latency I. These were similar to those in CGC, except for the significantly higher proportion of EBVaGC in GRC than in CGC, suggesting that there is no more aggressive EBV variant in EBVaGC in GRC, and the injuries of gastric mucosa and/or changes of the microenvironment within the remnant stomach may be involved in the development of EBVaGC in GRC. This, to our knowledge, is the first study concerning about the EBV genome polymorphisms of EBVaGC in GRC in the world.