EPSTEIN-BARR-VIRUS INFECTION AND THE PATHOGENESIS OF NASOPHARYNGEAL CARCINOMA - VIRAL GENE-EXPRESSION, TUMOR-CELL PHENOTYPE, AND THE ROLE OF THE LYMPHOID STROMA

Nasopharyngeal carcinoma (NPC) is the human tumour showing the most co nsistent association with Epstein-Barr virus (EBV). The recent detecti on of EBV in in-situ NPC lesions has shed light oil the sequence of ev ents leading to the development of invasive NPC, and will be discussed in the context of what is known about EBV infection in non-neoplastic epithelial cells. The association of EBV with different histotypes of NPC will also be considered. EBV gene expression and NPC tumour cell phenotype will be discussed, and evidence will be presented suggesting that the lymphoid stroma characteristically found in undifferentiated NPC is a prerequisite for the development of this tumour.