Screening for Lung Cancer

You may qualify for lung cancer screening if you:

• are 55 to 80 years old
• have smoked cigarettes every day for at least 20 years (it does not have to be 20 years in a row, which means there could be times when you did not smoke), and
• have Ontario Health Insurance Plan (OHIP) coverage

If you meet these criteria, you should talk to your doctor or nurse practitioner about being referred to an Ontario Lung Screening Program (OLSP) location, or you can contact a location directly.

Not everyone who is referred to the OLSP will qualify to get screened. An OLSP location will call you to learn more about your risk of getting lung cancer and ask questions about your health and smoking history. Based on your answers to these questions, they will figure out your risk score and tell you if you qualify for lung cancer screening.

The risk score tells you your chance of getting lung cancer in the next 6 years. For example, if your risk score is 10, your chance of getting lung cancer in the next 6 years is 10%. People with a 2% or greater risk of developing lung cancer over the next 6 years are eligible to participate in the OLSP.

For location details, see Ontario Lung Screening Program Locations.

People who are not at high risk of getting lung cancer should not get screened because there may be more potential harms than potential benefits of screening for them.

If you think you have any signs or symptoms of lung cancer, speak with your doctor or nurse practitioner. Screening may not be right for you.

You do not qualify for lung screening if you:

• have been diagnosed with lung cancer
• have been coughing up blood with unknown cause
• have had unexplained weight loss of more than 5 kilograms (11 pounds) in the past year
• are being monitored, or undergoing testing or treatment for life-threatening conditions (for example, a cancer with a poor prognosis)
• have been told by an Ontario Lung Screening Program (OLSP) location that you do not qualify for lung cancer screening based on your risk score

Your risk of developing lung cancer can change over time. If an OLSP site tells you that you do not qualify for screening, you should check again in 3 years to see if you qualify.

You should check again sooner if you have:

• started smoking again (if you had quit)
• been told you have chronic obstructive pulmonary disease (COPD)
• a new family history of lung cancer

While screening can help find lung cancer early, screening tests are not perfect and can have potential harms. For people at high risk of getting lung cancer, the potential benefits of finding cancer early are probably greater than the potential harms of screening. When making a decision to screen, it is important to think about the potential benefits and potential harms and your own values and preferences – or what matters most to you.

Potential benefits of regular lung screening

• Getting screened regularly with a low-dose CT scan can find lung cancer earlier, which may mean that:
  • the chance of dying from lung cancer is lower
  • treatment may have a better chance of working
  • fewer treatments may be required and the treatments may be less invasive (easier to handle)
• Screening can be part of taking an active role in protecting your health and can be reassuring for some people

Potential harms of regular lung screening

• Low-dose CT scans may cause false positives. Some low-dose CT scans will show a nodule that needs more testing. Usually this follow-up test is another low-dose CT scan. Most people who have more tests will not have cancer.
• Lung cancer screening may find a cancer that is growing very slowly and would never make you sick or cause you any harm. Unfortunately, it is usually not possible to tell which cancers are more harmful.

If you qualify to get screened, Ontario Lung Screening Program locations can support you in making a decision about whether screening is right for you.

People who are at high risk of getting lung cancer and qualify to get screened will be offered a type of computed tomography (CT) scan that uses a small amount of radiation. This test is called a low-dose CT scan.

During the scan, the screening participant lies on an open table that passes through a large donut-shaped machine called a scanner. The scanner uses a small amount of radiation to take detailed pictures of the lungs. The test only takes a few minutes and is not painful. There are no medications or needles given during the test.

Lung cancer screening is available at 10 hospital locations in Ontario. The Ontario Lung Screening Program is expanding and will be available in more locations across the province in 2026.

For locations and contact information, see Ontario Lung Screening Program Locations.

Quitting smoking is one of the best things you can do to improve your overall health, including reducing your chances of getting cancer.

Quitting can be hard, but it is possible, and you are more likely to quit if you get help. If you currently smoke and come to one of the Ontario Lung Screening Program locations, you will be offered free services to help you quit smoking. You can also contact the following services directly for support:

• Call a quit coach at Health811 by calling 811 (TTY: 1-866-797-0007). Getting help over the phone through a quit line can more than double your chance of quitting.
• Visit SmokersHelpline.ca to access self-help materials and join an online group of quitters and quit coaches.

Find more resources to help you quit smoking:

• One Step at a Time (Canadian Cancer Society)
  • For Smokers Who Want to Quit
  • For Smokers Who Don’t Want to Quit
  • Help a Smoker Quit
• Journey 2 Quit (Lung Health Foundation)
• On the Road to Quitting (Health Canada)
• Indigenous Tobacco Program
• Be Tobacco-Wise - First Nations
• Be Tobacco-Wise - Inuit
• Be Tobacco-Wise - Métis