Cancer treatment could see people heal themselves, researchers say
Compounds used in the treatment teach the body's immune system to destroy cancer cells
Dr. Shashi Gujar describes the new melanoma immunotherapy treatment he's researching with the old adage: give a man a fish and he eats for a day; teach him to fish and he eats for a lifetime.
But in this case, the treatment teaches the immune system to get rid of cancer on its own rather than relying on temporary treatment.
"If we really trained our immune system to identify all the threats that could come on board, that's it — that's like the holy grail of your health," said Gujar, an assistant professor of pathology and a cancer researcher with Dalhousie University's faculty of medicine.
"And these novel approaches which are coming on board, that's what these are trying to do."
5-year $3.2M grant
Gujar and his research team received a five-year, $3.2-million grant last month from the National Cancer Institute in the U.S.
Together with his research collaborator Sherri McFarland, who works at the University of North Carolina, Dalhousie and Acadia, and Halifax surgeon Dr. Steven Morris, Gujar is looking into the use of photo-sensitive ruthenium metal-based compounds to treat metastatic melanoma.
When the compounds are applied to melanoma lesions and activated by a certain wavelength of light, they kill the melanoma cells.
At the same time, Gujar said, the compounds teach the body's immune system to destroy cancer cells. Ideally, this will help patients stay cancer-free.
"In pre-clinical testing, it has shown really promising results," he said.
Cancers are formed out of normal tissue, so it's often difficult for the immune system to recognize them as a threat, Gujar said. His treatment relies on immune cells called T cells, which can be trained to target specific identifiers that only exist on melanoma.
Melanoma begins as a cancerous mole on the skin and in early stages can be treated using surgery, radiation therapy and chemotherapy. As it spreads through the body, fewer treatment options are available.
The survival rate for metastatic melanoma is about 18 per cent in Canada. More than 1,200 Canadians died of the disease last year, according to the Canadian Cancer Society.
'Educated' T cells do the work
Gujar hopes his T cell immunotherapy will improve those numbers.
"If your melanoma is metastasizing in your bone, in your lungs, T cells have access to those sites," he said. "Those T cells can now go on and target those niches, following their education."
Brian Thompson is the CEO of the Dalhousie Medical Research Foundation. He said Gujar's research is part of a wider collaborative approach to immunotherapy research, much of which is funded through the foundation. Scientists are working to create better tools for predicting where cancers will emerge and ways of creating immunities to cancers.
Thompson said that could lead to a reduction in chronic care for cancer patients, shorter treatment and recovery times, and fewer incidences of cancer.
"I would call this research world-class," he said.
Many immunotherapies don't make it past clinical trials. Further research sometimes discovers they cause the immune system to attack healthy cells as well as cancer cells. But Gujar remains optimistic because immunotherapy has only been a treatment option for a few years.
"The pace with which science is going, I'm pretty sure that as we streamline these immunotherapies, there will be lesser and lesser side effects."
Gujar hopes that by the end of the five-year grant, his team will have a few compounds ready to go into clinical testing on humans.