Association of Epstein-Barr virus and nasopharyngeal carcinoma in Caucasian patients

We evaluated the association of nasopharyngeal carcinoma (NPC) and Epstein-Barr virus (EBV) in Spanish patients, and studied the expression of EBV products (latent membrane protein–1 [LMP-1] and ZEBRA proteins) by NPC cells and its possible prognostic value. In situ hybridization (ISH) for EBV-encoded nonpolyadenylated RNAs (EBERs) and immunohistochemical expression of LMP-1 and ZEBRA proteins by immunohistochemistry were examined in formalin-fixed, paraffin-embedded NPC specimens from 30 patients, and a survival analysis was done by the Kaplan-Meier method. We detected EBERs by ISH in 96.67% of the NPC cases, and detected expression of LMP-1 in 43.33% of the NPC cases and expression of ZEBRA protein in 6.67% of the NPC cases. We conclude that ISH for expression of EBERs is an adequate method for detection of EBV in NPC. LMP-1 is not frequently expressed in NPC cells (43.33%). Most NPC cells carry a latent EBV infection. LMP-1 expression might have worsened the prognosis of NPC in our series.