- Lung Condition
Lung Cancer
Lung cancer is the growth of abnormal cells inside the lung that divide and form a tumour. Early detection is critical — the sooner it is diagnosed, the better the opportunity for curative treatment.
#1
Cause of cancer deaths in Canada
85%
Most commonly diagnosed cancer in Canada
Radon
2nd leading cause — test your home
Low-dose Computed Tomography
Recommended screening for high-risk adults
- Overview
- Symptoms
- Causes
- Screening
- Diagnosis
- Treatment
Overview
What is lung cancer?
Lung cancer is the growth of abnormal cells inside the lung. These cells divide and grow more quickly than normal cells, forming a tumour — a cluster of cells. If cancer starts in the lungs, it is called primary lung cancer. It can also spread (metastasize) to other parts of the body.
Lung cancers are divided into two main types based on where cancer started: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Other types include mesothelioma and carcinoid tumour.
85%
Non-Small Cell Lung Cancer
The most common form. Includes squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Tends to grow and spread more slowly than SCLC.
15%
Small Cell Lung Cancer
Less common but grows and spreads quickly. Almost always caused by smoking. Usually diagnosed at a later stage. Also includes mesothelioma and carcinoid tumour.
Symptoms
Recognising lung cancer
Lung cancer is much easier to treat when detected early. However, many people do not experience symptoms until the disease has progressed to a later stage. Symptoms can differ for each person.
Persistent or worsening cough
A cough that doesn't go away or gets worse over time.
Coughing up blood
Blood or rust-coloured sputum (spit or phlegm)
Chest pain
Often worse with deep breathing, coughing, or laughing
Shortness of breath
Unexpected breathlessness during normal activities
Hoarseness
Unexplained change in voice quality
Unexplained weight loss
Significant loss of appetite or weight without cause
New onset of wheezing
Wheezing that is new and not related to asthma or allergies
Recurring infections
Bronchitis or pneumonia that doesn't go away or keeps coming back
Headaches, bone pain, or blood clots
May indicate cancer has spread to other parts of the body
Fatigue or weakness
Feeling persistently tired or weak without explanation
- Speak to your healthcare provider
If you experience any of these symptoms, consult your healthcare provider. Many lung cancer symptoms resemble other conditions, but getting the proper diagnosis is imperative and can be lifesaving. Discuss your risk factors and whether further lung cancer screening is right for you.
Causes
Risk factors for lung cancer
Smoking is the leading cause of lung cancer, but not everyone who develops lung cancer smokes. Several other factors can increase your risk.
-
Smoking (leading cause)Smoking (leading cause) Smoking is the #1 cause of lung cancer. Exposure to second-hand smoke also increases your risk. Quitting smoking is the best thing you can do for your overall health and to prevent lung cancer.
-
Radon (second leading cause)Radon (second leading cause) Radon is a radioactive gas from the natural breakdown of uranium that can build up in homes. It is the second leading cause of lung cancer, which is why testing your home for radon is critical. Smokers exposed to high radon levels face an even greater risk.
-
Personal history of cancer or lung diseasePersonal history of cancer or lung disease A history of COPD, pneumonia, tuberculosis, or other cancers such as mouth or throat cancer can increase your risk of developing lung cancer.
-
Genetics and family historyGenetics and family history Genetics can increase your risk of developing lung cancer. If others in your family have had lung cancer, be sure to tell your healthcare provider.
-
Hazardous chemical exposureHazardous chemical exposure Working with asbestos, uranium, arsenic, cadmium, chromium, nickel, and certain petroleum products significantly increases lung cancer risk.
-
Air pollution and environmental factorsAir pollution and environmental factors Air pollution from motor vehicles, factories, and power plants contains microscopic particles, nitrogen oxides, diesel exhaust, benzene, and polycyclic aromatic hydrocarbons — all harmful to the lungs and known to increase cancer risk.
Screening
Early detection saves lives
Two thirds of lung cancers are diagnosed late-stage. Screening uses tests or exams to find a disease in people who may not have symptoms. In lung cancer, early detection is everything — the sooner it is diagnosed, the better the opportunity for curative treatment.
The Canadian Task Force on Preventive Health Care recommends screening with three consecutive annual low-dose CT (LDCT) scans for high-risk individuals: adults aged 55–74 who currently smoke or quit less than 15 years ago, with a smoking history of at least 30 pack-years. A pack-year is the average number of packs smoked daily multiplied by the number of years smoking.
Alberta Lung supports updated screening recommendations to improve outcomes for non-smokers.
Diagnosis
How lung cancer is diagnosed
A diagnosis usually starts with a visit to your healthcare provider, who will take a medical history, perform a physical exam, and arrange certain tests. They may refer you to a specialist or order further tests to confirm a diagnosis.
-
Medical history & physical examMedical history & physical exam Your healthcare provider will ask about unusual symptoms and possible risk factors, and look for physical signs of lung cancer or other health problems.
-
Imaging testsImaging tests Imaging is used to rule out or identify lung cancer and to determine the stage (how far it has spread). Common imaging includes chest X-ray, CT scan, PET scan, MRI, and bone scan.
-
Lab testsLab tests The actual diagnosis is made by looking at lung cells in a lab. Samples may be collected via sputum cytology, thoracentesis (fluid removal), or biopsy (needle or surgical).
Imaging tests
X-RAY
Chest Radiography
Often one of the first tests to look for abnormal areas in the lungs.
CT SCAN
High Resolution CT (HRCT)
More detailed than a chest X-ray. Shows size, shape, and position of any tumours. More likely to detect early lung cancer.
PET SCAN
Positron Emission Tomography
A slightly radioactive form of sugar (FDG) injected into the blood collects mainly in cancer cells, revealing their location.
MRI
Magnetic Resonance Imaging
Uses radio waves and magnets to create detailed images of soft tissue. Most often used to check for spread to the brain or spinal cord.
Tests to confirm cancer cells
LAB TEST
Sputum Cytology
A sample of mucus (coughed up from the lungs) is examined in the lab to check for cancer cells.
Fluid test
If fluid has collected around the lungs (pleural effusion), some is removed and tested to determine whether cancer has spread to the lung lining.
Biopsy
Needle Biopsy
A hollow needle is used to get a small tissue sample from a suspicious area without a surgical incision.
Biopsy
Surgical Biopsy
A surgeon takes a lung tissue sample through small chest incisions. Done under general anaesthetic. A pathologist examines the cells under a microscope.
Treatment
Treatment options
Treatment for lung cancer varies depending on the type and stage of cancer. Your healthcare team will discuss the options best suited to your situation.
Chemotherapy
Uses drugs to stop or slow the growth of cancer cells
Surgery
Removes the tumour and surrounding tissue from the lung
Radiation Therapy
Uses high-energy rays to destroy cancer cells in the lung
Immunotherapy
Helps the immune system recognise and fight cancer cells
Targeted Treatments
Drugs that target specific proteins or genes in cancer cells
Home Oxygen
May be prescribed if blood oxygen levels are low — not a cure, but supports quality of life
- About home oxygen
Talk to a specialist
Free, confidential lung health line. Mon to Fri, 8:30 am – 4:30 pm.
Related conditions
- COPD
- Mesothelioma
- Pulmonary Fibrosis
- Radon Exposure
Resources
-
Asthma action planAsthma action plan PDF · 2 pages
-
Trigger tracking diaryTrigger tracking diary
-
Inhaler technique guideInhaler technique guide
-
How to use a peak flow meterHow to use a peak flow meter