B.C. researchers developing breath test for lung cancer

Marla Kott was diagnosed with Stage 4 lung cancer on Nov. 21, 2014. It was her 60th birthday.

"It was not a great day," said Kott, who was was one of thousands of people in Canada diagnosed with lung cancer that year.

The disease accounts for a quarter of cancer deaths, according to the Canadian Cancer Society. The society says the five-year survival rate is 62 per cent for those diagnosed with Stage 1 lung cancer, and drops to three per cent for Stage 4.

It took about a year for Kott to be diagnosed, after undergoing numerous tests to determine what was wrong.

A lung X-ray of a cigarette smoker in an undated photo. (American Cancer Society/Getty Images)

Against the odds, Kott is still going strong nine years later — but the Vancouver resident wishes there had been a way to detect her cancer sooner.

"I might have been able to have surgery and be done with it," she said, imagining scenarios in which the disease was discovered early and fully treated.

"I wouldn't be on drugs or living with it or being tested a lot. I would have been cured, so to speak. Now I will never be cured. I will always have cancer."

Researchers with B.C. Cancer in Vancouver are now working to develop a breath test that could help show signs of cancer earlier, and screen more people, more easily.

"When we exhale, we exhale over 1,000 volatile organic compounds," said team co-lead Dr. Renelle Myers, adding that some of these compounds have the potential to indicate cancer development.

Myers first began studying breath samples in 2020, when she opened what she says is the first clinical breath lab in Canada. When the pandemic hit, her team pivoted from cancer research to looking at the detection of COVID through breath.

"If we can find that fingerprint of an early lung cancer, that will help us screen, much more easily, many, many people around the province and around the world."

Story continues

Additionally, researchers hope the test will help them understand how changes in the lungs might indicate cancer development in people who have never smoked.

"We are seeing an alarming increase of lung cancer in never-smokers," Myers said.

A study published by B.C. Cancer in June 2023 found that 33 per cent of lung cancer patients in Vancouver had never used tobacco products, and suggested air pollution might be the cause — in particular, a particle called PM2.5, levels of which are higher in B.C. during wildfire season.

AI organizing data

The test researchers are working on uses artificial intelligence to sift through data.

"There's thousands of compounds in a single breath," Myers said, adding that AI helps organize people by age, risk factors and other indicators of cancer.

"Even if our team works 24/7, we couldn't process all the samples required for these large, multi-centre studies with only the system we have now," research team co-lead Dr. Stephen Lam said. "Especially since samples can't be stored for very long once collected."

Currently, the best way to diagnose lung cancer is through a CT (computed tomography) scan, Myers said. But other tests, including blood tests, X-rays, MRIs, ultrasounds and biopsies, to name a few, can be part of the determination.

"The majority of patients who are diagnosed with lung cancer are diagnosed at a late stage when they become symptomatic," Myers said.

The team is in the early stages of nationwide clinical study, having collected nearly 300 samples from individuals in Ontario, B.C. and Quebec. The goal is to look at samples from 4,000 people.

They're looking at pulmonary nodules — small clumps of cells in the lungs — that are often benign but can develop into cancer.

Researchers will follow patients over five years to see how those nodules develop and how breath signatures change in turn.

By being able to identify if a nodule is not cancerous, Myers said patients could be given the all clear, and not have to follow up for several months.

"It's powerful in that it could potentially really reduce downstream resource utilization in our health-care system," she said.