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.
This transcript has been edited for clarity.
Hello. I’m Dr Ticiana Leal. I’m a thoracic medical oncologist and director of the thoracic oncology program at the Winship Cancer Institute of Emory University in Atlanta, Georgia. Today I will be providing lung cancer screening updates.
As background, most patients present with advanced-stage lung cancer at initial diagnosis. However, in the decades since the United States Preventative Services Task Force first recommended lung cancer screening in 2013, we have seen a shift, and the proportion of early-stage diagnoses has increased, and fewer patients are now diagnosed at late stages. The goal of any screening, including lung cancer screening, is to detect the disease early when it is not causing symptoms and when the treatment will be most successful.
The current recommendation is for low-dose CT, which is based on the results of two very important trials called the National Lung Screening Trial (NLST) as well as the NELSON trials. These trials showed that lung cancer screening improved overall survival and likely drove the shift in diagnosis from advanced to early-stage disease.
The screening recommendations have been broadened in order to increase rates of early detection and to increase uptake of lung cancer screening for populations at high risk for lung cancer. Some of the recommendations include broadening or removing the upper age limit. Previously, screening was recommended for ages 55-74, but now the American Cancer Society recommends annual low-dose CT screening for individuals aged 50-80 years old.
Eligibility criteria in patients with a smoking history have also broadened. Patients now qualify if they currently smoke, or have ever smoked, regardless of when they quit, with at least a 20-pack-year history (down from 30). Importantly, current smokers should also have access to smoking cessation support.
One thing that we also need to work on is broadening screening for high-risk populations and to also include underrepresented patients.
A study presented at ASCO 2025 demonstrated that in high-risk populations, such as those in the Mississippi Delta, the rates of lung cancer diagnosis and incidental pulmonary nodules were much higher than in the NLST trial — more than fourfold greater than the 1.1% observed — demonstrating the impact of lung cancer screening in the higher risk population.
Certainly there are patients that are still ineligible for lung cancer screening. However, smoking exposure still remains a critical factor to assessing risk and determining a favorable risk-benefit ratio for screening.
For patients with no smoking history, at this time, they are ineligible for lung cancer screening. This goes for individuals younger than age 50 and those who have less than a 20-pack-year smoking history. Also, patients who have risk for secondhand smoke are not eligible for lung cancer screening.
If an individual thinks they are high risk for lung cancer yet do not currently fit the screening criteria, it is important to discuss this with their healthcare provider. They may be eligible for clinical trials evaluating broader screening as we continue to learn more about people at risk for lung cancer.
It is important to note that patients with symptoms suspicious for lung cancer — such as cough or shortness of breath — are not eligible for screening. They should instead undergo a diagnostic CT scan. For those with an abnormal CT scan during screening, radiologists use specific criteria called the Lung-RADS to classify the risk of lung cancer for that individual.
Depending on risk stratification from the radiology findings, patients may be advised to schedule a follow-up sooner than 1 year or, in some cases, to have a biopsy. Many patients with identified lung nodules may be monitored more closely, and some institutions now offer lung nodule clinics to ensure appropriate follow up. Importantly, finding a lung nodule on a lung cancer screening test does not mean the patient will ever develop lung cancer, but it may mean that they need closer monitoring.
Future investigations are required to reduce the risk of high false-positive rates. In clinical trial settings, blood tests are being incorporated to help identify patients at higher risk of lung cancer during screening. I would also like to emphasize the importance of increasing lung cancer screening rates — not only in the US but worldwide.
I believe these are all positive changes and very important for us to address. Thank you very much for listening.