Epstein-Barr virus genomes in undifferentiated and squamous cell nasopharyngeal carcinomas in Italian patients

Although undifferentiated carcinoma (UC) and squamous cell carcinoma (SCC) of the nasopharynx are regarded as two distinct histopathologic and clinical entities, it is unclear whether, like UC, SCC carries Epstein-Barr virus (EBV) genomes. We used the polymerase chain reaction (PCR) on paraffin-embedded biopsy specimens to test for the presence of EBV DNA in 20 cases of UC and 9 cases of SCC. Multiple copies of the viral genome were regularly detected in all UCs; however, of the nine cases of SCC, seven had no detectable EBV DNA and two contained viral genomes in a low copy number. In parallel, a marked difference in the serum levels of anti-EBV antibodies between patients with UC and SCC was found. Our findings provide evidence for the specific association of EBV with UC in Italian patients and prove by means of a highly sensitive molecular technique that SCC is occasionally related to EBV DNA. Because of the absence of EBV DNA in most cases of SCC and the minimal viral DNA copy number in the few EBV-associated cases of SCC, a different pathway of oncogenic transformation and growth of the nasopharyngeal epithelium is suggested for SCC and UC.