Four-year-old Rory Nichols, shown in this undated handout image, had a genetic test that determined she was at risk for hearing loss from a chemotherapy drug so her mother decided to switch her to another medication after discussions with a doctor at BC Children’s Hospital. THE CANADIAN PRESS/HO

Scientist wants risks of kids’ cancer drugs tested across the country

Scientist wants genetic test across Canada to gauge risks of kids’ cancer drugs

A scientist who developed a lab test to predict whether children with cancer are susceptible to potentially life-threatening side effects from three chemotherapy drugs is now focusing on five other medications so parents and doctors can discuss safer, personalized treatment.

Bruce Carleton, director of the Pharmaceutical Outcomes Programme at BC Children’s Hospital, said adverse reactions linked to the five medications include bone disease, pancreatitis, anaphylaxis, nerve damage in the limbs, and inflammation of the mucous membranes, including those that may prevent patients from swallowing.

The four-year project is part of a Genome Canada study that will include the creation of a publicly available genetic database that could be accessed by researchers around the world, Carleton said.

He and his colleague Colin Ross have already identified genetic variants linked to three commonly prescribed drugs that cause heart failure, hearing loss or suppression of bone marrow, which reduces the body’s ability to fight infections.

For the last two years, cancer patients Carleton has seen at a BC Children’s Hospital clinic have been given a genetic test to determine if they are at risk for reactions.

Carleton said he would like children at all cancer centres in Canada to be genetically tested for adverse reactions to the potent medications.

Related: B.C. woman to walk across Europe following cancer diagnosis

They include anthracycline, which plays a role in dramatically improving survivability rates of many cancers but also causes heart failure in some cases.

“I think that we can begin the conversations before treatment begins about what the adverse effect means, instead of waiting for it to occur and saying, ‘Well, this happens sometimes,’ ” Carleton said. “Often, parents say to me that the adverse effects of cancer chemotherapy were harder for them to manage and deal with than the survival questions because they’re not prepared for it.”

Their research includes analysis of over 6,100 DNA samples as they work to discover genetic susceptibility to side effects from the five drugs in the expanding field of pharmacogenomics.

Genetic testing provides oncologists with information that can help them weigh the risks and benefits of some treatment as they consider options that may include lowering the dosage of a toxic drug or providing an alternative therapy, he said.

“Sometimes the results are reassuring, that if you need to exceed the dose, the likelihood of toxicity is fairly low compared to other children,” said Carleton, who is also a professor of pediatrics at the University of British Columbia.

Parents need to be part of the treatment discussion, he said.

“Coming up with a way for them to better understand what their child’s risk is allows them to say, ‘Survival isn’t the only thing. I also want to know about harm,’ ” he said.

Bethany Prokuda’s four-year-old daughter Rory Nichols was diagnosed with a tumour at the tip of her tail bone about three weeks after she was born.

She said genetic testing soon after Rory’s first birthday revealed she was on a chemotherapy drug that put her at over 80 per cent risk of hearing loss related to F, S and “th” sounds in words such as Friday, Saturday and Thursday.

Prokuda, a registered nurse, said she decided to switch her daughter to a different medication after discussing options with Rory’s oncologist.

“If they can give them an answer and maybe be able to tailor the therapies so that these kids do have good outcomes, it’s absolutely essential,” she said of genetic tests.

Prokuda said she began speech therapy for Rory, who is currently doing well while trying to keep up with her eight-year-old sister Avery.

“She’s definitely progressed better from where it was. From age two to age four she’s caught up on a lot of those sounds,” Prokuda said.

“She’s singing along to music, she’s copying her big sister reading books, it’s really good.”

Dr. Rod Rassekh, who has treated Rory, along with her primary oncologist, said the genetic test “really helped spare a lot of her hearing.”

Rassekh said the parents of one of his patients who was tested decided they wanted their child taken off a drug that would cause heart problems, even if that put the youngster at slightly higher risk of relapse.

“So that’s what I think this test does, is facilitates really good discussions with families, where they can be empowered to make decisions.”

Rassekh said all oncologists at BC Children’s Hospital now routinely use genetic testing, even though they were initially concerned about what they and parents would do with the information it provided.

“What it’s allowed us to do is actually have very open discussions about side effects and consider parents’ values and what they deem important. What they think is high risk may not be what I think is high risk as a doc.”

Related: Support pouring in for Penticton boy fighting cancer

Camille Bains, The Canadian Press

Like us on Facebook and follow us on Twitter.

Just Posted

ZONE 8: Gabby Knox is a 2nd-generation BC Summer Games competitor

Both parents competed in softball, but Knox of Williams Lake is making waves in the pool

This year’s 25th anniversary of Tour de Cariboo to be the last

This year’s Tour de Cariboo fundraiser will celebrate 25 years of memories.

Tl’etinqox community strengthed by 2017 wildfires, says chief

Residents denied evacuation order to help themselves

West Fraser continues burned timber salvage in the Cariboo Chilcotin

Two cutting permits will allow the company to harvest 227,000 cubic metres of burnt timber

2017 fire babies pose for photo one year later

23 babies and their moms gathered for a photo shoot at the Williams Lake Fire Department

All-Indigenous teams break new ground, making BC Games history

This is the first time there have been dedicated Indigenous teams at the BC Summer Games

Ping-pong balls of fire dropped to merge two B.C. wildfires

The merger is considered successful by BC Wildfire Services

Canada to resettle dozens of White Helmets and their families from Syria

There are fears the volunteers would become a target for government troops

Francesco Molinari wins British Open at Carnoustie

It is his first win at a major and the first by an Italian

Government sets full-time salary range for Justin Trudeau’s nanny

At its top range, the order works out to a rate of $21.79 per hour, assuming a 40-hour work week

ZONE 7: Players’ insistence delivers North West softball team to BC Games

North West hasn’t had a girls softball team since 2010 but that changed at the Cowichan Summer Games

Recovery high schools could help teens before addiction takes hold: B.C. parents

Schools could provide mental health supports and let parents discuss their children’s drug use openly

Haida Gwaii village faces housing crisis, targets short-term rentals

Housing is tight and the village is pretty close to zero vacancy

Evacuation numbers remain at nearly 1,000 as B.C. wildfires rage on

200 firefighters and 18 helicopters were working to increase the containment of the fires

Most Read