Herpes simplex virus. An expanding relationship to human cancer.

Herpes simplex virus (HSV) causes a wide spectrum of infectious disease in humans. During the past 15 years, evidence has accumulated indicating that, in addition, HSV may be a cause of human cancer, particularly cervical cancer. The research on HSV has taken five directions. First is detection of previous infection with HSV 2. This was the earliest approach and was performed largely with serologic assays. Studies showed a higher incidence of infection with HSV-2 in cervical cancer patients as compared with matched controls. Second is searching for evidence of HSV markers in premalignant and malignant lesions. Viral antigens and nucleic acids have now been demonstrated directly in transformed cells. Antibodies to viral proteins suggestive of abortive infection have been shown to be present in high percentages of cervical cancer patients. Third is searching for in vivo evidence of HSV oncogenic potential. HSV has been shown to be capable of transforming cells in culture. Attempts are being made to determine the fragment of viral DNA responsible for transformation. Fourth is development of animal models for virus-induced cervical cancer. A mouse model is showing promise. Fifth is studying the expanding relationship of HSV to other human cancers. Cancer of the vulva has recently been associated with genital HSV infection.