As the rates of late-stage lung cancer in nonsmokers rise in Canada, researchers are advocating for increased awareness and screening.

According to the Canadian Cancer Society, lung cancer was estimated to account for 24.3% of all cancer deaths in 2022. This proportion was more than colorectal, pancreatic, and breast cancer deaths combined. The Society estimates that roughly a quarter of lung cancer cases in the country affect nonsmokers.

The Canadian Partnership Against Cancer noted that patients whose lung cancer is detected early have a better chance of recovering than patients who are diagnosed later. But in Canada, patients with lung cancer are more likely to be diagnosed at an advanced stage (ie, stage III or IV) than patients with breast, prostate, or colorectal cancer.

A Smoker’s Disease?

The common thinking is that lung cancer is a smoker’s disease, but that isn’t the full picture, Jessica Moffatt, PhD, vice president of programs and health system partnerships at Lung Health Foundation in Toronto, told Medscape Medical News. “The only thing it takes to get lung cancer is having a pair of lungs. All of us have a risk for lung cancer,” she said. “We still don’t have a map of genetic profiles or exposure that equates with someone having a diagnosis of lung cancer.”

Moffatt and her colleagues are working to dispel the stigma that smokers “get what they deserve.” Rosalyn Juergens, MD, professor of oncology at McMaster University in Guelph, Ontario, and president of Lung Cancer Canada, said, “If you find out someone has lung cancer, your first question shouldn’t be ‘Did you smoke?’ It should be ‘What can I do to help you along this journey?’”

“The vast majority of patients with lung cancer will enter late-stage disease at some point in their cancer journey, with nearly half being diagnosed initially at the late stages,” Geoffrey Liu, MD, senior scientist at the Princess Margaret Cancer Centre in Toronto, told Medscape Medical News. “The incidence varies by city and province, based on demographics, but it’s roughly 20%,” said Liu. He highlighted the lack of awareness among the public, patients, and physicians regarding the incidence of lung cancer in nonsmokers. Many of his nonsmoker patients with lung cancer are completely shocked by their diagnosis. When they search online, most of the information focuses on smoking and lung cancer. Liu and Juergens are working with family doctors to raise awareness of the risk in nonsmokers. “Many of them had previously thought lung cancer in nonsmokers was a rarity,” said Liu.

“Unfortunately, these cases are sometimes diagnosed late, as patients often don’t develop symptoms until the cancer has begun to grow and spread,” said Lawson Eng, MD, a medical oncologist and researcher at the Princess Margaret Cancer Centre and an assistant professor of medicine at the University of Toronto, Toronto. Another reason for late diagnosis is that symptoms such as coughing tend to go unnoticed or be ignored by patients and physicians.

Early Screening Needed

Clinicians may be less likely to investigate respiratory symptoms in nonsmokers, potentially overlooking early warning signs, according to Moffat, who previously led the Ontario Lung Screening Program. She stated that a major contributor to late-stage diagnosis is the design of current lung cancer screening programs, which primarily target older adults with a significant smoking history. As a result, nonsmokers — especially younger women — are rarely screened proactively.

“Unlike for patients who have smoked, where there is evidence and support for lung cancer screening, for patients who have never smoked, we currently don’t have any guidelines related to lung cancer screening, and this is another area of ongoing active research,” added Eng.

“We’ve realized that lung cancer isn’t one disease. Now, we’re able to do molecular testing on tumors,” said Juergens. “There are now more than a dozen molecularly defined subtypes of lung cancer. Getting that information is vitally important because if you’ve got one type of the disease, I might have a tablet for you, and even if your cancer has spread to your bones, brain, or liver, you might live for a decade or more. We can now match the subtype with the right treatment, whether it’s a tablet, chemotherapy, chemotherapy combined with immunotherapy, or immunotherapy alone,” she added.

The prognosis for these patients varies depending on the stage of the cancer, said Eng. “When caught early, lung cancer is potentially curable, but if it has spread elsewhere, often it is not curable. The prognosis for patients with advanced lung cancer depends in part on the molecular profile of the lung cancer. Other factors include how well the patient is, their ability to tolerate treatment, and their response to treatment.”

The chances of surviving 5 years with lung cancer have doubled in the past 15 years, noted Juergens. She views immunotherapy as a game-changer in improving lung cancer survival rates. “Twenty years ago, when I was giving people chemotherapy as their only option, I told them there was only a 1 in 5 chance it would shrink their tumor at all.” This led many patients to refuse the treatment. “Now, if I’ve got the right profile, with stage IV cancer I tell them they have a 1 in 3 chance of still being here 5 years later. We only got national access to next-generation sequencing in the past couple of years, during the COVID-19 pandemic. It solidified all the infrastructure needed to make this a reality,” Juergens concluded.

Moffatt, Juergens, Liu, and Eng reported having no relevant financial relationships.

Evra Taylor is a widely published freelance medical writer and reporter with 20 years’ experience covering a broad range of therapeutic sectors, including family health, cardiology, psychiatry, ophthalmology, and dermatology.