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Guidelines for Lung Cancer Screening

British Columbia Specific Information

Low dose computed tomography (CT) scans search the lungs for signs of lung cancer, as well as other lung diseases. Early detection using low dose CT scanning has been shown to reduce lung cancer deaths by 20%. The BC Lung Screen Trial provides the only access to organized lung cancer screening to eligible B.C. residents. Participants must be 55-80 years of age, be a current smoker or former smoker, and have smoked for 20 years or more. To learn more about the BC Lung Screen Trial program, see BC Cancer – The BC Lung Screen Trial and BC Cancer – Lung.


Lung cancer screening is a way to find some lung cancers early, before a person has any symptoms of the cancer.

Lung cancer screening may help those who have the highest risk for lung cancer—people 55 to 74 who are or were heavy smokers.footnote 1 For most people, who aren't at increased risk, screening for lung cancer probably isn't helpful.

Screening won't prevent cancer. And it may not find all lung cancers. Lung cancer screening may lower the risk of dying from lung cancer in a small number of people.


Lung cancer screening programs are not available in all areas. Lung cancer screening is recommended for people ages 55 to 74 years old who are or were heavy smokers.footnote 1 That means people who have a smoking history of at least 30 pack years. A pack year is a way to measure how heavy a smoker you are or were.

To figure out your pack years, multiply how many packs a day on average (assuming 20 cigarettes per pack) you have smoked by how many years you have smoked. For example:

  • If you smoked 1 pack a day for 30 years, that's 1 times 30. So you have a smoking history of 30 pack years.
  • If you smoked 2 packs a day for 15 years, that's 2 times 15. So you have a smoking history of 30 pack years.

Canadian experts recommend lung cancer screening every year up to three years in a row if:footnote 1

  • You are 55 to 74 years old.
  • And you have a smoking history of at least 30 pack years.
  • And you still smoke, or you quit within the last 15 years.

If you have a serious health problem, you and your doctor will decide if lung cancer screening is right for you.



  1. Canadian Task Force on Preventive Health Care (2016). Recommendations on screening for lung cancer. Canadian Medical Association Journal, 188(6): 425–432. DOI: 10.1503/cmaj.151421. Accessed December 10, 2019.


Current as of:
December 17, 2020

Author: Healthwise Staff
Medical Review:
E. Gregory Thompson MD - Internal Medicine
Kathleen Romito MD - Family Medicine
Adam Husney MD - Family Medicine