[Viral tumor markers].

Viruses can contribute to the development of human tumors by different mechanisms: directly by altering host cellular gene expression by viral products or by viral DNA integration; indirectly by modifying the host cell genome co-operated with other factors. Human cancer associated with hepatitis B virus (HBV), hepatitis C virus (HCV), human T cell leukemia virus (HTLV-I), papillomavirus (HPV) and Epstein-Barr virus (EBV) infections are responsible for liver cancer (HBV and HCV), adult T cell leukemia (HTLV-I), cervical cancer (HPV) and malignant lymphoma (EBV) respectively. Based on the clinical and experimental knowledge, viral tumor markers are thought of not as diagnostic markers, but as most important risk factors for various tumorigenesis.