Published On Feb 17, 2016
The Hen and the Hares
The 50-year crusade to prove the link between viruses and cancer
In 1910, a woman arrived at the Rockefeller Institute for Medical Research. She wanted the institute to treat the lump on the breast of her prized Barred Plymouth Rock hen. Fortunately for science, though unfortunately for the bird, it soon came into the hands of Francis Peyton Rous.
Rous, fresh out of medical school, had just been appointed head of the institute’s small research program investigating cancer. He was curious about how the disease spread. Rous diagnosed the tumor as spindle-cell sarcoma, chopped it into small pieces, then implanted fragments of the tumor into other parts of the chicken’s body and into other, closely related chickens. A month later, the original chicken was dead, and one of the others had developed a large growth.
A contagious form of cancer had never been documented before, but Rous repeated his experiments through four generations of related chickens with similar results. In one experiment, he mashed the tumor in a saline solution, then separated the cells with a centrifuge and filter. When he injected the remaining clear liquid, tumors continued to appear. This pointed to an infectious agent somehow distinct from the cells themselves, and much smaller—“probably a living virus,” Rous suggested in a 1912 paper.
Virology was still an emerging field, not applied to human pathology until experiments with yellow fever in 1901. But Rous couldn’t find many colleagues who accepted the idea that a virus could cause cancer, and he was unable to achieve similar results in mice.
World War I brought other research priorities—Rous worked on blood preservation and helped establish the first blood banks in the United States—but in 1934, fellow Rockefeller researcher Richard Shope identified hornlike “warts” that his jackrabbit subjects sprouted after infection with the papilloma virus. Rous identified the growths as tumors. In a medical lecture before the esteemed Harvey Society, Rous noted that “it may prove worthwhile” to draw the connection between some tumors and viruses.
It was not until 1966, more than 50 years after his first paper, that the idea won Rous the Nobel Prize. Some 20% of cancers, including cervical cancer, are now thought to originate from viral causes. This insight led to vaccinations that greatly lower the risk of this cancer for millions of women.