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Lung screening
The Ontario Lung Screening Program offers a risk assessment, and low-dose CT screening if eligible, to people 55–80 who have smoked tobacco daily for at least 20 years in total.
- Who may be assessed
- Usually people ages 55–80 with OHIP coverage who smoked tobacco daily for at least 20 years in total. Those years do not have to be in a row.
- What smoking counts?
- Cigarettes, cigars, loose tobacco, pipes and bidi/beedi. Vaping, cannabis, chewing tobacco or second-hand smoke alone do not meet this program’s smoking criterion.
- The test
- A low-dose CT scan, usually every year if the program finds you eligible. An assessment does not guarantee a scan.
- How to get started
- Ask a doctor or nurse practitioner for a referral, or contact a program location about an assessment. A clinician referral is needed before screening.
- A different care plan
- Symptoms need assessment. If you already have lung cancer or a lung nodule follow-up plan, keep following your care team’s advice.
What this page helps with
Lung screening uses a low-dose CT scan to look for early lung cancer in people at high risk who have no symptoms. This page explains the Ontario program's entry criteria, the difference between being assessed and being eligible, and how to get in touch. It does not estimate your risk — the program does that.
Symptoms are different from screening. If you have new or concerning symptoms, see a healthcare provider rather than waiting for a screening test. Severe or life-threatening symptoms: call 911 or go to the nearest emergency department. Otherwise a provider, a walk-in or urgent care clinic, or Health811 (811) for advice on where to go.
Who the routine guidance is for, and who needs another pathway
Who may be assessed. Ontario Health describes ages 55–80 with OHIP coverage and a history of smoking tobacco — cigarettes, cigars, loose tobacco, pipes or bidi/beedi — every day for at least 20 years in total. The 20 years do not need to be in a row, and the criterion is years of daily smoking, not pack-years and not time since quitting.
Assessment, then eligibility. Meeting the criteria allows a formal risk assessment by the program using several factors (age, smoking history, health history, family history and others). Only people whose assessed risk meets the program's threshold are eligible for screening. So contacting the program does not guarantee a scan.
Other exposures. Vaping, cannabis, chewing tobacco or second-hand smoke alone do not meet the listed smoking criterion. That is a statement about program entry, not that these exposures are harmless; symptoms still need assessment and quitting support is available.
Over 80. Some people age 81 or older may be considered after discussion with their clinician and the program. The referral criteria include the smoking-history and OHIP requirements, discussion of benefits and harms, being well enough to undergo and recover from treatment, and being expected to live long enough to benefit from it. A clinician referral is required for each yearly screening scan after age 80. This is not limited in the published referral criteria to existing participants, and assessment does not guarantee a scan.
When you need a different plan. Known lung cancer, lung nodule surveillance, or symptoms such as coughing up blood or unexplained weight loss follow a diagnostic or follow-up pathway, not new screening.
How to access it in Ontario
A family doctor or nurse practitioner can refer you. You can also contact a program location directly to ask about an assessment — Ontario Health lists participating hospitals, or call the Ontario Health cancer screening information line at 1-866-662-9233 for locations. A clinician referral is required before screening participation, and the program can advise on access for people without a provider. OHIP coverage is part of the criteria. See Getting screened.
Potential benefits and limitations
In people at high risk, screening can find lung cancer earlier, when treatment is more likely to be effective. Limitations: many scans show nodules that are not cancer and need follow-up scans; there is a small radiation dose with each scan; and screening does not remove the health risks of smoking. Screening may find lung cancer earlier, while stopping smoking reduces future health risks. Screening and support to quit have different, complementary benefits. Screening is not a way to investigate symptoms.
Screening can also find a cancer that would never have caused harm during a person’s lifetime. This is called overdiagnosis and can lead to unnecessary tests or treatment.
What the assessment and scan involve
The program contacts you for a risk assessment (usually by phone) and, if eligible, a conversation with a navigator about benefits and harms before you decide. The low-dose CT scan itself takes a few minutes, with no needles or contrast, lying on a table while it images your chest. Results go to you and your provider, with a repeat scan schedule if you continue in the program.
What happens after an abnormal result
Most nodules found are not cancer. Depending on size and appearance, the next step is usually a repeat CT after an interval, sometimes other imaging or a specialist review, and occasionally a biopsy. The program coordinates this; this page cannot interpret your result.
Questions to ask your provider or the program
- Do I meet the referral criteria, and what does the risk assessment involve?
- What are the chances of a false alarm and follow-up scans?
- I have quit — does that change anything?
- What support is there to stop smoking?
Sources
- More Ontarians can now access lung cancer screening (program eligibility and locations) — Ontario Health
- Lung Cancer Screening — Ontario Lung Screening Program site information — Michael Garron Hospital
- Lung screening referral criteria, including the over-80 pathway — Ontario Health / Cancer Care Ontario
- Lung screening assessment, benefits and harms — Ontario Health / Cancer Care Ontario
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