Researchers Use Common Viruses To Fight Cancer
For years, doctors have treated cancer with three things: chemicals, radiation and surgery. New research finds another approach holds promise – giving cancer a cold…a cold virus.
Some Columbus oncologists are studying how common viruses can treat tumors and cancer cells.
In part the second of our three-part series on cancer, WOSU’s Mandie Trimble reports the experimental treatments have shown some success.
Virus as a foe of cancer is not a new theory.
Nationwide Children’s Hospital Dr. Tim Cripe oversees oncology and blood and marrow transplantation.
“It’s really an idea that’s been around for over 100 years,” Cripe said. “There was a talk in 1905 or so by a physician, in Cleveland, where they were noticing that people that had cancer, and there were no treatments available for them, got natural infections and some of them had some cancer regression. So they were actually postulating back then that maybe we could harness nature’s ability to infect tumors and treat them.”
Now researchers are discovering how to do it. In Columbus, doctors are working with familiar viruses, such as the common cold and herpes viruses, to infect and kill cancer cells. Children’s is experimenting with the herpes virus.
“Essentially, we’re trying to give cancer a cold sore, but the virus we’re using won’t cause a normal cold sore,” Cripe said.
Doctors have crippled the viruses. They’ve removed out a gene so the virus only targets the cancer.
“It will actually infect and kill cells and destroy, cause an ulcer in the tumor,” Cripe said.
While the cold sore virus is known for infecting the lip, Cripe says it can infect tissues throughout the body, which makes it useful in attacking many cancer types. Depending on what kind of cancer, doctors may directly inject a tumor or give an intravenous treatment.
Researchers around the world are testing different viruses – measles, polio, even some from animals like cows and rabbits.
Over at Ohio State’s James Cancer Hospital, researchers are experimenting with the common cold virus to treat glioblastomas – very aggressive brain tumors.
Dr. Vinay Puduvalli directs OSU’s neuro-oncology department. Because glioblastomas are confined to the brain…
“A needle is placed directly inside the tumor, and you can inject the virus in multiple places. There are some trials in which the tumor is taken out first and the virus is injected into the walls of the tumor cavity where there are microscopic tumor cells,” Puduvalli explained.
Puduvalli says they’ve treated about 50 patients. A small number in the study have done very well.
“Sometimes those patients would go three or four years without tumor growth, and that is remarkable for a glioblastoma that has grown back because people don’t last more than a few months when you have tumors like that,” Puduvalli said. “So the fact that we are getting even a small number of patients who are having these very long survivals is the reason why this research is so very promising.”
Researchers suspect the viruses could have a lasting effect against the tumor, similar to how a vaccine works against disease. Puduvalli calls that a “bonus.”
“So if that happens in select patients, you may have an immune system effect on the tumor that may prevent it from growing back even if it survives that first attack,” Puduvalli said.
Doctors stress these treatments are in early phase trials. Researchers first must test for safety and dosing. The next step would be testing to see how well they work.
But right now, Nationwide Children’s Dr. Cripe says these trials could help some patients whose cancers have not responded to other treatments.
“This gives them some hope.”
For patients with aggressive brain tumors, Puduvalli says he thinks science is closer to its goal of long, quality life.
“The word cure in brain tumors has not been frequently used,” Puduvalli said. “People are very cautious about using that word. But when you see responses with the regrowing tumors with no growth for three to four years, you being to wonder if you have reached a stage where you can begin to talk about it.”