Relation of Herpes Simplex Viruses to Human Malignancies

We have been asked to provide our evaluation of the available data concerning the role of herpes simplex viruses in human malignancies. Perhaps we can begin by stating a set of criteria which, if fulfilled, would satisfy us that a particular virus was the causative agent of a particular malignancy. These requirements will form the framework around which the topic will be developed. Of course, we do not wish to imply that these criteria are original or that the form in which we have stated them is unique. These criteria include the following points: (1) There should be some epidemiologic or biological association or link between the malignancy and the suspected virus; (2) Purified preparations of the virus should induce tumors in its natural host or a similar species, and the resulting tumors should be similar to naturally occurring ones; (3) Ideally, one might hope to find similar naturallyoccurring malignancies in other animals caused by similar viruses; (4) The virus should transform cells in culture, and transformed cells should induce tumors similar to naturally occurring ones, and conversely, tumor cells cultured in vitro should be similar to transformed cells; (5) It should be possible to prevent the malignancy by preventing infection with the suspected virus. Needless to say, the different criteria carry different weight, and fulfillment of the second or fifth criteria stated above would provide very strong evidence for an etiologic role of the virus.