N.S. researchers probe possible link between allergies and cancer
Researchers at Dalhousie University in Halifax, N.S. are engaged in fascinating research to understand why people with certain allergies seem to be more protected from cancer than those without.
Dr. Jean Marshall, from the university’s Department of Microbiology and Immunology, says her team is trying to understand if there’s anything about the medications that allergy sufferers take or whether it’s the allergies themselves that might explain why this group has a lower risk of developing cancer.
“It brings together information that we have from epidemiology that we've always been curious about -- why some people with allergic disease are protected from certain types of cancer,” she tells CTV Atlantic.
With the help of a three-year cancer research “innovation grant” from the Canadian Cancer Society, Marshall’s research team is looking at how histamine – the compound our blood cells emit that causes immune responses, such as sneezing, rashes and swelling – might affect cancer.
They’re also looking at how antihistamines, the drugs that block histamine, might affect the spread of tumours.
In recent years, a number of epidemiological studies have noted that allergy-prone people seem less likely to develop a number of forms of cancer, including colorectal and pancreatic cancer, and even childhood leukemia.
“More recently, people have started to put together these small studies and analyze them in a bigger basis in something called meta-analysis, where you bring together the results of numerous studies,” says Marshall. “And when you put the studies together, they really paint a much stronger picture of there being an important association between allergic disease and certain forms of cancer.”
Why a link may exist isn’t known, but it’s becoming clear that the body’s immune response is an important player in cancer development.
It’s possible that because allergy sufferers have overactive immune systems trained to respond to foreign substances, they naturally seek out cancer cells and fight them off. Or, it could have something to do with the medications they take.
If that’s the case, any discoveries could be translated quickly to cancer patients, because antihistamine medications are already approved for human use.
“We'll have two years to sort of explore these hypotheses and hopefully come to some findings,” Marshall says.
Marshall and her colleague Sharon Oldford, a postdoctoral research fellow at Dalhousie, will be conducting lab experiments to determine what effect – if any – histamine and antihistamine drugs have on tumour growth. “So it will be informative whether we actually determine there is a cause and effect. Or if we show that there is no effect, it will still be very informative.”
The Canadian Cancer Society’s innovation grant is a new funding program that aims to support unconventional theories about cancer that, if they pan out, could have an impact on a large number of people.
“It could be that they discover some better way to treat, a better way for doctors to manage cancer,” says Barbara Stead-Coyle, the CEO of the Canadian Cancer Society in Nova Scotia. “What we’ve discovered, because of the way the Canadian Cancer Society funds research and that we fund all cancers, that a breakthrough in one area many times ponies on and becomes a breakthrough in many areas.”
Researchers caution that this project is in its early stages, but they hope that if their work produces good information about the relationship between cancer growth and allergies, they can receive another grant for further study.
With files from CTV Atlantic's Jacqueline Foster