Carcinoma of the cervix: can a viral etiology be confirmed?

The etiological role of viruses in various animal cancers is no longer in doubt; a similar role in human cancers is, however, yet to be confirmed. Indeed, until recently, virus infections were considered to be responsible for only a small proportion of the clinical states encountered in humans and the view that viruses may be etiological agents for human malignant tumours was not seriously entertained. With the introduction of more advanced techniques in immunovirology, the role of viruses in clinical syndromes the etiology of which had been obscure became clearer. The Emory University Group first postulated in 1964 an association between herpes simplex virus (HSV) infection and cervical neoplasia, following studies of an infant with neonatal HSV infection and his mother's cervical HSV infection. This postulate was based on the observation that women with genital HSV (herpes simplex virus type-2 (HSV-2] infection have a greater frequency of cervical neoplasia than women in the general population. Demographic surveys of cancer of the cervix have established patterns of high risk that strongly suggest that the disease may be transmitted venereally. Similarly, evidence has accumulated to show that HSV-2 is a sexually transmitted disease. It has thus been postulated that this virus may be an initiating or promoting carcinogenic factor transmitted to the female during sexual intercourse. Various multicentric approaches, from epidemiological studies to molecular studies, have been employed to substantiate this association. Even though the weight of circumstantial evidence supporting the role of HSV-2 in human carcinoma of the cervix has increased, no definitive 'cause-and-effect' association has been established between the virus and carcinoma of the cervix. The question arises, therefore, whether or not an etiological association between the virus and the disease can be confirmed. To prove a definitive cause-and-effect relationship, further studies will be required, such as the recent demonstration of the involvement of papillomavirus.