Epstein-Barr virus DNA is not increased in tonsillar carcinoma

Epstein-Barr virus (EBV) is a known oncogenic virus associated with a wide variety of cancers, including nasopharyngeal carcinoma. Waldeyer's ring, a collection of lymphoid tissues, includes the nasopharynx, pharyngeal, and l ingual tonsils, To determine if EBV plays a causative role in carcinomas ar ising from other tissues in Waldeyer's ring, we examined pharyngeal tonsill ar carcinomas for evidence of EBV infection. As previously reported, DNA wa s extracted from 53 consecutive tonsil cancers, as well as from age- and ge nder-matched non-cancerous tonsillectomy specimens. Three different sets of primers for discrete exons of EBV were then used to determine if active or latent EBV infection was expressed in the extracted DNA using the polymera se chain reaction (PCR). Ah positive bands were then sequenced to confirm t he presence of amplified EBV fragments, None of the samples showed evidence for active EBV infection. In primers demonstrating latent infection, 1 of 53 (1.9%) of tumors were positive, versus 6 of 53 (11.3%) of the controls. These results indicate that EBV expression is not increased in DNA from ton sil cancers and that EBV infection does not have a causal relationship with tonsil cancer.