Prevalence and relevance of EBV latency in nasopharyngeal carcinoma in Israel

Abstract

Background: Nasopharyngeal carcinoma (NPC) is frequently associated with Epstein-Barr virus (EBV). The incidence of NPC in Western countries is lower than in the Far East, and EBV latency in NPC is less prevalent. Israel, as a part of the Mediterranean area, is one of the countries with an intermediate risk for NPC. Methods: Immunohistochemistry (IHC) for latent membrane protein 1 (LMP-1) and in situ hybridisation (ISH) for EBV encoded RNA (EBER) were used to evaluate the prevalence and possible prognostic value of EBV latency among Israeli patients with NPC. Forty five patients with different NPC histologies were studied. Results: LMP-1 IHC was positive in six samples only, all with undifferentiated histology. EBER ISH was positive in 40 of the 45 samples. According to histological type, three of five patients with squamous cell carcinoma were EBV positive and 37 of 40 non-keratinising and undifferentiated carcinoma cases were positive. Although EBV was more prevalent in patients with non-squamous carcinoma, the difference was not significant, probably because of the small number of patients with keratinising carcinoma. With regard to the clinical categories and survival, no significant difference could be detected between patients who were positive or negative for EBER ISH. No association was found between EBV latency and patient sex, age, origin, stage, or survival. Conclusions: NPC in Israel is highly associated with EBV latency as detected by EBER ISH. LMP-1 IHC is considerably less sensitive in detecting EBV latency in NPC among the same patient group.

HLA Class II Alleles and the Presence of Circulating Epstein-Barr Virus DNA in Greek Patients with Nasopharyngeal Carcinoma

“…We also found that all three histological types of NPC were associated with the presence of EBV. Our results are consistent with previous reports which suggest that NPC in the Mediterranean basin resembles the Asian type and is strictly associated with the EBV infection [2,13,40].…”

Lymphoepithelial Carcinoma with Special Reference to Nasopharynx-A Study of 35 Cases

“…Out of 35 cases of lymphoepithelial carcinoma10 cases were found in the younger age group(10-20 )yrs and 8 cases in the older age group(61-80) yrs,Balakrishnan et al 6 observed bimodal age distribution with peaks in age group (15)(16)(17)(18)(19)(20)(21)(22)(23)(24) and (45-54) yrs from India.…”

Downregulation of expression of transporters associated with antigen processing 1 and 2 and human leukocyte antigen I and its effect on immunity in nasopharyngeal carcinoma patients

“…Previous studies on normal nasopharyngeal tissue and premalignant biopsies indicated that genetic events occur early in the pathogenesis of NPC and they may predispose to subsequent EBV Downregulation of expression of transporters associated with antigen processing 1 and 2 and human leukocyte antigen I and its effect on immunity in nasopharyngeal carcinoma patients infection. The EBV latent-gene expression in NPC is predominantly restricted to the Epstein-Barr nuclear antigen 1, the latent membrane proteins (LMP) 2A and 2B and the BamHI-A transcripts, with approximately 70% of the tumors also expressing the oncogenic LMP1 protein (9)(10)(11). Currently, research is focused on the mechanisms underlying the escape of NPC from EBV-specific immune destruction and the development of novel strategies for immune intervention.…”