Background: Certain viruses, notably human papillomavirus (HPV), cytomegalovirus (CMV), herpes simplex virus (HSV) and Epstein-Barr virus (EBV), are known to produce tumors in animals and cell transformation in vitro and they have been implicated in the pathogenesis of human cancers. All these viruses are also known to infect the esophagus. This study was aimed to determine whether these viruses play any causal role in the etiology of esophageal squamous cell carcinoma.
Materials and methods: A series of 103 esophageal squamous cell carcinomas derived from patients in the high-incidence area of northern China were analyzed by DNA in situ hybridization and polymerase chain reaction (PCR) for the presence of HPV DNA sequences and, using immunohistochemistry, for the demonstration of CMV, HSV and EBV infections.
Results: Six (5.8%) of the 103 tumors were found to contain HPV 16, 18 or 30 DNA sequences. HPV types 6, 11 and 53 were not detected in any of the cases. Amplified HPV DNA sequences were found in 17 out of 101 (16.8%) carcinoma specimens by PCR with L1 consensus primers. None of the 103 carcinomas tested was immunohistochemically positive for CMV, HSV or EBV.
Conclusion: Our results confirmed the HPV involvement in esophageal carcinomas and provided further evidence to support a causal association of HPV infection with esophageal squamous cell carcinoma. However, the three herpesviruses, CMV, HSV and EBV, are highly unlikely to be involved in the pathogenesis of this malignancy in the high-incidence area of China.