Epstein-Barr virus and human papillomavirus infections and oropharyngeal squamous cell carcinomas

Epstein-Barr virus (EBV) and human papillomavirus (HPV) are known to exhibit oncogenic potential. Target cells for both viruses include oropharyngeal elements. The present study investigated whether EBV or HPV infection are associated with palatine tonsil carcinoma (PTC) and/or tongue carcinoma (TC). The study included 28 adult patients with oropharyngeal squamous cell carcinoma, including 14 patients with PTC and 14 patients with TC. The control group included 20 healthy adult volunteers. Sera of all patients and controls were tested for IgG anti-EA antibodies, IgG anti-VCA antibodies, and IgG anti-EBNA antibodies. DNA extracted from the tumors was tested for the presence of EBV DNA and HPV DNA using PCR-ELISA. In parallel, the presence of EBV DNA was tested in the peripheral blood in all healthy individuals and patients. In addition, attempts were made to detect HPV 16 and HPV 18 using other PCR amplification techniques. Serum anti-EBV antibodies were detected in 24 patients (12 patients with PTC and 12 patients with TC). The frequency of detection of the antibodies did not significantly differ between the groups of patients and the control individuals. Most positive patients and controls demonstrated a serological pattern typical for past EBV infection. EBV DNA was identified in 12 cases of PTC and in 12 cases of TC (altogether 86% cases). In 10 PTC patients, 8 TC patients, and only 2 healthy individuals EBV DNA was detected in peripheral blood. HPV DNA was detected in only 3 cases (1 sample of PTC and 2 samples of TC). These results suggest that the etiopathogenesis of oropharyngeal cancers may be associated with EBV infection much more frequently than with HPV infection.