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The Hottest Thing. "Right now," says National Cancer Institute's Heller, "the hottest thing in cancer is research on viruses as possible causes." The Rockefeller Institute's Dr. Peyton Rous showed as long ago as 1911 (his findings were unpopular at the time) that one cancer (sarcoma) in chickens is caused and can be transmitted by a virus. Over the years, viruses were found to cause other tumors in birds and lower animals. But the gap between them and man seemed unbridgeable. Then the University of Minnesota's Dr. John J. Bittner showed that breast cancer in certain mice is transmitted by a factor, now accepted as a virus, in mouse mothers' milk. This led to the establishment of mouse "dairies," and the painstaking milking of tens of thousands of rodents. In 1951, Dr. Ludwik Gross of The Bronx Veterans Administration Hospital injected something (evidently a virus material) from leukemic mice into newborn mice, got a high incidence of leukemia and some odd tumors to which little attention was then paid.
Other researchers promptly tried to duplicate Gross's results. One was Dr. Sarah E. Stewart, a tall, vivacious microbiologist turned physician and working in Baltimore for the National Institutes of Health. As so often happens in medical research, she did not get what she was looking for, but she got something better. Many of the mice she injected with Gross's "leukemia virus" got solid tumors, mainly in the parotid (salivary) glands. (Dr. Heller's theory: the Gross material had contained two viruses.) Dr. Stewart teamed with the NIH's Dr. Bernice E. Eddy to grow the solid-tumor virus in tissue cultures of monkey kidney cells (as polio virus is grown to make Salk vaccine).
Vaccination? By now, the SE (for Stewart-Eddy) polyoma (multiple-tumor) virus has hurdled the species barrier and caused cancers not only in mice but in rats and in Syrian and Chinese hamsters. In rabbits, for some strange reason, it causes only benign tumors. So far, Drs. Stewart and Eddy have not been able to infect monkeys with their virus, but a determined effort to do so is under way at Roswell Park Institute. Patricia, a lone baby monkey harboring polyoma virus, has her own spotless nursery where she is cared for by Nurse Althea Higgins. Drs. Stewart and Eddy have gone a vital step farther, treated their virus with rabbit serum, and made a vaccine that protects a big majority of normally susceptible animals against the polyoma virus' effects. At Sloan-Kettering Institute, Dr. Charlotte Friend has cultured a strain of mouse virus that causes leukemia in adult as well as newborn animals, and has perfected a protective vaccine. So in some animals, the circle of evidence is virtually complete: viruses are linked with leukemia and certain tumors, and immunity is offered through vaccination.