A virus that cause respiratory illnesses and stomach upsets in children could help in the fight against primary liver cancer, according to a study. Reovirus stimulates the body’s own immune system to kill off the cancerous cells and is also able to kill off the hepatitis C virus – a common cause of primary liver cancer – at the same time, the researchers at the University of Leeds discovered.

These early stage findings are important because primary liver cancer is the third highest cause of cancer deaths worldwide and, if surgery is not an option, the prognosis is poor. Study co-leader Dr Stephen Griffin, Associate Professor of Viral Oncology at the University of Leeds, said: “Ultimately we hope that by simultaneously treating the tumor, and the hepatitis virus that is driving the growth of the tumor, we may provide a more effective therapy and improve the outcomes for patients.

“Current treatments for liver cancer that can’t be removed by surgery are mainly palliative with chemotherapy only tending to prolong life, rather than cure and it can have significant side effects.” The University of Leeds team found that Reovirus was successful in treating both liver cancer cells grown in the laboratory and those taken directly from patients undergoing surgery.

When introduced into the body, Reovirus stimulates an immune system factor known as interferon, which in turn causes the activation of a specific white blood cell called a Natural Killer cell. These Natural Killer cells then kill both the tumor, and cells infected with the hepatitis C virus.

Stimulating the immune system to kill cancer cells is known as immunotherapy. It differs from chemotherapy, in which the actual drugs kill the cancer cells. The researchers are now hoping to start the first in-human clinical trials. Study co-leader Professor Alan Melcher, now Professor of Translational Immunotherapy at the Institute of Cancer Research, London, said: “Our study establishes a completely new type of viral immunotherapy for the most common primary liver cancer type, hepatocellular carcinoma, which has a very poor prognosis in its advanced form.