Epstein-barr virus early ribonucleic acids as a diagnostic adjunct for relapsed metastatic tumors in patients with cured primary undifferentiated nasopharyngeal carcinoma

Abstract

Epstein-Barr virus (EBV) has been consistently shown to be associated with undifferentiated nasopharyngeal carcinoma (NPC). In this article, the authors attempt to detect Epstein-Barr virus in distant relapsed metastatic sites in undifferentiated NPC patients with cured primary cancer. In situ hybridization (ISH) technique is a reliable method to detect EBV early RNAs (EBERs) within NPC cells. We used a nonisotopical ISH technique to examine the presence of EBERs in paraffin-embedded tissues obtained from 1 paired specimen of primary NPC and its metastatic counterpart at liver and 2 metastatic specimens of retroperitoneal lymph nodes and bone. All the primary lesions and the metastatic tumors of NPC with undifferentiated histology contained EBERs that could be clearly detected in the nuclei of cancer cells. This article shows that EBERs can be successfully detected in cells of the distant relapsed metastatic sites. These results suggest that this nonisotopical ISH method of EBERs can be potentially used to diagnose NPC patients developing distant relapsed metastatic lesions with cured primary cancer early. It can offer quick information as to institute suitable salvage chemotherapy for these patients.