This term is currently very rare. The name for the field of study, virotherapy, has been known for a decade but has only occasionally strayed outside specialist or academic publications. The magazine Scientific American explained its meaning succinctly in a headline to an article in October 2003: “virotherapy harnesses viruses, those banes of humankind, to stop another scourge — cancer”.
Anecdotal reports have appeared for more than a century that certain viruses can counter tumours, but it has only been in the past couple of decades that a growing understanding of genetics has enabled medical researchers to begin developing treatments using oncolytic (cancer-attacking) viruses. The then state of the art was summed up in a report two years ago:
Research has shown that virotherapy, in which viruses are programmed to attack cancer cells, leaving healthy cells undamaged, could be beneficial, but this treatment is at present experimental.
Daily Telegraph, 21 Mar. 2011.
The field has moved on since then. A viral therapy to treat prostate cancers and one to help treat cancers of the head and neck are currently working their way towards approval in the US. Others are stymied for lack of funding.