Oncogenic viruses and cancer.

Abstract

This special issue of the journal is dedicated to the important topic of oncogenic viruses and cancer. It contains seven review articles covering all known oncogenic viruses except for human T-lymphotropic virus type 1 (HTLV-1). These review articles are contributed by experts on specific viruses and their associated human cancers. Viruses account for about 20% of total human cancer cases. Although many viruses can cause various tumors in animals, only seven of them are associated with human cancers and are currently considered oncogenic viruses. These viruses include hepatitis B virus (HBV), hepatitis C virus (HCV), human papillomavirus (HPV), Epstein Barr virus (EBV), human herpes virus 8 (HHV8), Merkel cell polyomavirus (MCPyV), and HTLV-1. HBV and HCV cause approximately 80% of hepatocellular carcinoma (HCC), the most common cancer of the liver. High-risk HPV strains are the major causes of cervical cancer and other ano-genital neoplasms as well as a significant proportion of head and neck tumors. EBV is associated with nasopharyngeal carcinoma, Hodgkin’s lymphoma, and Burkitt’s lymphoma. HHV8 (also called Kaposi’s sarcoma-associated herpesvirus,KSHV) is responsible for Kaposi’s sarcoma often found in patients with acquired immunodeficiency syndrome (AIDS). MCPyV causes Merkel cell carcinoma and HTLV-1 is the causative agent of adult T-cell lymphoma.