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Lung

​This information should not be used for self-diagnosis or in place of a qualified physician's care.

Reviewed 2016

The basics
  • Guidelines for treating this cancer have been developed by the Lung Tumour Group.
  • For health professional information on treating this cancer, please see our Cancer Management Guidelines.
  • Other names for lung cancer are: pulmonary cancer, bronchial cancer, small cell lung cancer (SCLC), oat cell carcinoma of the lung, non-small cell lung cancer (NSCLC), adenocarcinoma of the lung, squamous cell lung carcinoma of the lung. Another type of cancer that can occur in the lining on the outside of the lung is called mesothelioma and is described separately.
  • It is important to know whether a cancer in the lung is primary or secondary. Primary lung cancer starts in the lungs. This webpage discusses primary lung cancer.
    • The lungs are also a common secondary site for cancer. Secondary tumours in the lung started at a different place in the body and then moved (metastasized) to the lungs. Cancer can travel to the lungs using the lymphatic system or through the blood. Types of cancers that usually move to the lungs are breast, colon, kidney and pancreas, among others. The treatment for metastases may be decided by where the cancer started, not where it spread.
  • The lungs are located in the chest. They wrap around the heart and the major blood vessels going to and from the heart and esophagus.
  • The right lung has three sections, also called lobes, and the left lung has two lobes.
  • The lungs and inner walls of the chest are lined with a thin double membrane called the pleura, which normally touch the lungs and move easily during breathing.
  • How we breathe:
    • Air is inhaled into the pharynx (back of the throat), down the trachea (windpipe) and finally into the bronchi, which are two tubes that take the air to the lungs.
    • The main bronchial tubes (or bronchi) branch into smaller tubes within each lobe and then again into bronchioles ending in the alveolar ducts.
    • Alveolar ducts lead to tiny thin-walled clusters of sacs called alveoli. The average lung has about 300,000,000 alveoli. We breathe in and out and the following happens:
      • Oxygen enters the blood system through the alveoli.
      • Carbon dioxide and other waste gases exit the blood system through the alveoli and out of the body.

What causes it and who gets it?

Listed below are some of the known risk factors for this cancer. Not all of the risk factors below may cause this cancer, but they may be contributing factors.

  • Tobacco smoking is the number one cause of lung cancer.
    • About 85 - 90% of lung cancer patients are smokers, former smokers or people exposed long-term to second-hand smoke. Exposure to other people's smoking is also called 'passive smoking'.
    • Tobacco smoke contains many toxic chemicals capable of causing cancer. There are about 4,000 chemicals in cigarette smoke; more than 50 of those are known to cause cancer.
    • The average smoker will die about eight years earlier than a non-smoker.
    • Each year tobacco smoke kills about 45,000 people in Canada.
    • People exposed to second-hand smoke over many years are also at risk. Babies and children are particularly at risk from second-hand smoke because their lungs are developing, and proportionately they breathe in more of the harmful substances found in tobacco smoke.
  • Exposure to uranium or other radiation sources, and heavy metals such as chromates, arsenic and nickel can cause lung cancer.
  • People with a history of chronic bronchitis or emphysema are at higher risk for lung cancer.
  • Asbestos dust can cause lung cancer.
  • People who have survived one lung cancer are at risk of a second cancer, especially if they continue to smoke.
  • A number of other factors, such as diet, may have an effect on the development of lung cancer, but not enough is known. More research is needed to establish risk factors.
  • Beta-carotene supplements are known to increase the risk of lung cancer in smokers.
  • People with a past history of mouth or throat cancer have a higher risk of lung cancer.
  • British Columbia has the lowest rate of lung cancer in Canada, and also the lowest mortality rate from lung cancer.
  • Lung cancer is most common in the 55 - 70 year age group, but in recent decades it has doubled in the 40 - 44 year old group and increased ten-fold in the 60 - 64 year group.
  • Lung cancer is the leading cause of cancer death for both men and women. About 26% of all cancer deaths are from lung cancer.
  • Statistics

Can I help to prevent it?

Prevention holds the greatest hope for the future.

Never starting to smoke or quitting smoking, helps to prevent lung cancers.

If you quit smoking, your risk of lung cancer goes down; more for each year that you haven't smoked. 10 years after quitting, the risk of dying from lung cancer is about half that of a person who is still smoking.

Screening for this cancer

  • There is currently no known method for screening for lung cancer, although there are many studies going on around the world to try to develop a good screening method.
  • The BC Cancer Agency is currently enrolling people in a project called the Lung Health Study. The focus of the study is the early detection of lung and bronchial cancer, and the identification of new agents that may halt or slow the growth of abnormal cells in these organs.
    • Eligibility for Lung Health Study:
      • a current or former smoker
      • between 45 - 74 years of age
      • have smoked for at least 30 years
    • The Lung Health Study uses a lung imaging fluorescence endoscope (LIFE), a light sensitive camera attached to a bronchoscope, to detect pre-cancerous areas and/or early lung cancers too small to detect on chest x-rays or by conventional bronchoscopy alone.
    • The LIFE system illuminates the airways with a blue laser light and a computer analyzes the images and displays them on a colour monitor.
    • A physician can then tell the abnormal areas, shown as red, from normal areas, shown as green.
    • Tiny tissue samples are taken from abnormal (red) areas so a pathologist can confirm what exactly has been found. People who have:
      • abnormal cells that are not cancer - may be invited to participate in the chemoprevention trial.
      • cancer - will be treated for their cancer.
      • healthy lungs - will be thanked for their time and their contribution to science.
    • For more information contact the Lung Health Study, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, B.C., V5Z 1L3. Phone 604.675.8088 or 1.888.675.8001 x 8088.
    • In Victoria, phone 250.519.5720 or 1.800.670.3322 x 5720.

Signs and Symptoms

  • The early stages of lung cancer often have no symptoms. Because of this, most lung cancer patients already have advanced disease by the time they are diagnosed.
  • Symptoms of later, more advanced stages may include:
    • New, changing or worsening cough, especially if the sputum contains blood
    • Change in the ability to perform exercise (e.g. shortness of breath with walking)
    • Blood in sputum, even small amounts
    • Wheezing (not related to asthma or infection)
    • Hoarse voice
    • Repeated episodes of pneumonia and/or bronchitis
    • Fever, weakness, weight loss
    • Chest pain
    • Difficulty swallowing
    • Growth of lymph nodes in the neck
    • A sudden urge to quit smoking (rare)
    • Clubbing (broadening) of the fingernails (rare)
  • Advanced lung cancer tends to spread through blood and the lymphatic system. Lung cancer frequently spreads (metastasizes) to the brain, liver, bone and lymph nodes.
    • Symptoms from the spread of lung cancer may be noticed before symptoms occur from the lung cancer itself.
Diagnosis & staging

Diagnosis

These are tests that may be used to diagnose this type of cancer.

  • A chest X-ray is one of the most useful examination tools.
  • CT (computerized tomography) scans can show in 3D the relationship of the lung cancer to other structures of the chest, and can show the possible spread of cancer to the lymph nodes.
    • MRI magnetic resonance imaging may be useful in some circumstances.
  • PET (Positron Emission Tomography) scans can be used to look at lung cancers and assess the relationship to other structures in chest and show possible spread to other organs.
  • To make a diagnosis of lung cancer, cells must be examined under a microscope.
    • Cells may come from sputum samples, pleural fluid (fluid on the lungs), brushings or washings of the bronchi (sample gathered from a bronchoscopy) or from a biopsy (sample) of the lung cancer.
    • A bronchoscopy is a procedure that can be used to diagnose lung cancer and determine the extent of the disease. This is usually performed with a fibre-optic bronchoscope, which is a flexible viewing tube with lighting. The bronchoscope is inserted down the throat into the trachea and bronchi. It can also grab bits of tissue, and a biopsy may be taken at this time. A local or general anesthetic may be used.
    • A needle biopsy may also be used for diagnosis. The doctor is guided by a CT scan or x-rays and inserts a needle through the chest wall into a suspected tumour and draws out a tissue sample. Lung collapse may be a complication with this procedure.
    • Thoracentesis is the removal of fluid from the chest. A needle is inserted through the chest to the space between the lung and the chest wall to draw out fluids. This can be used for diagnosis to look at the cause of fluid on the lungs. This can be used to analyze the fluid, or to relieve shortness of breath caused by large amounts of fluid in the pleural space. Occasionally this is combined with a procedure called a pleurodesis, to stick the lung to the chest wall. This usually involves the placing of a tube in the chest for one to three days during a hospital stay to ensure that all of the fluid has been removed.
  • A mediastinoscopy and mediastinotomy can provide information on the spread to lymph nodes and is performed under general anesthetic.
    • A mediastinoscope is inserted through a small v-shaped incision at the centre of the base of the neck and passed behind the sternum (breastbone) to lie directly in front of the trachea. Lymph nodes on either side can be seen and biopsied.
    • A mediastinotomy involves a cut near the 2nd rib to gain access to the lymph nodes under the aorta. This is used in patients who have centrally located tumours in the left upper lobe.
  • If there are lymph nodes that can be felt when a physician examines the patient, a needle biopsy may be performed.
  • A diagnostic thoracotomy (surgically opening the chest to look at the lungs) may be necessary if other diagnostic procedures fail.
  • Pleuroscopy is not used often, but can be valuable for patients who have undiagnosed fluid in the chest. A thoracoscope or fibre-optic bronchoscope is inserted into the pleural space. All of the space can be examined visually and fluid and tissue samples can be taken.
For more information on tests used to diagnose cancer, see our Recommended Websites, Diagnostic Tests section.

Types and Stages

Types
There are two major kinds of lung cancer, small cell and non-small cell.
  • Small cell lung cancers (SCLC) make up 10-15% of lung cancers.
    • An older term for this kind of cancer is "oat cell" cancer, because of the shape of the cells. They are generally small and round, or oval, or shaped like oat grains.
    • This is the most aggressive and fast-growing of all lung cancers.
    • Many patients have spread to other organs (distant metastases) at the time of diagnosis even if the primary tumour is small.
    • Usually, small cell lung cancers are not treated surgically.
    • Multidrug chemotherapy with radiation therapy is the usual treatment. Prophylactic (preventive) whole-brain radiotherapy may also be used.
    • A long term cure is possible in about 20% of patients if the tumour is only in the chest (called 'limited stage').
    • Small cell lung cancer is staged referring to limited (disease is isolated to an area that could be treated with a single field of radiation treatment) or extensive (disease is bulky or in multiple areas)
  • Non-small cell lung cancers (NSCLC) – About 80% of all lung cancers are non-small cell. This category includes a number of different kinds of lung cancer. Some of them are squamous cell carcinoma, adenocarcinoma, and large cell (undifferentiated) carcinoma.
    • Squamous cell carcinoma (epidermoid)
      • About 30% of all NSCLC lung cancers are squamous cell.
    • Adenocarcinoma
      • About 40-50% of NSCLC lung cancers are adenocarcinomas.
      • This is the most commonly diagnosed lung tumour in women.
      • Non-smokers more frequently have this type of lung cancer.
    • Large cell carcinoma
      • This type of lung cancer occurs less frequently than other cell types (about 10%).
      • Generally this cancer behaves like the adenocarcinomas with aggressive spread.
    • Less common kinds of non-small cell lung cancer are adenosquamous carcinoma and carcinoid.
Stages 
Staging describes the extent of a cancer. The TNM classification system is used as the standard around the world for staging non-small cell lung cancers. In general a lower number in each category means a better prognosis. The stage of the cancer is used to plan the treatment. 

T describes the site and size of the main tumour (primary) 

N describes involvement of lymph nodes 

M relates to whether the cancer has spread (presence or absence of distant metastases). 

Stage I
The tumour is contained, and has not spread. 

Stage II
The cancer has spread to lymph nodes within the lung. 

Stage III
Cancer is found in the lymph nodes outside the lung, in the centre of the chest and/or the primary tumour has invaded the chest wall or central structures within the chest. 

Stage IV
The cancer has spread to other parts of the body.
Treatment

Treatment

Cancer therapies can be highly individualized – your treatment may differ from what is described below.

Treatment choices depend on the type of lung cancer (small cell versus non-small cell) and the desired outcome of treatment (cure versus symptom control / palliation).
  • Standard treatments for lung cancer may include surgery, radiation therapy (also called radiotherapy) and chemotherapy.
  • Some very early lung cancers may be treated with a fairly simple laser therapy.
  • Most patients have more than one type of treatment; they have a combination of therapies.
Surgery
  • Surgery is effective for small, localized tumours with no spread outside the lung. In these cases, it may cure the lung cancer.
  • Types of surgery:
    • Segmented or wedge resection – the removal of part of a lobe of one lung.
    • Lobectomy – the removal of a lobe of one lung.
    • Pneumonectomy – the removal of an entire lung.
  • Rarely, surgery can relieve symptoms (palliative care) or remove metastases.
Radiation Therapy
  • Radiation Therapy (also called radiotherapy) is given through a machine that delivers high powered x-rays. This treatment can be intended to cure or to relieve symptoms.
    • Radiotherapy may be given when cure is not possible because it can relieve symptoms such as cough, hemoptysis (blood in the sputum), chest pain and dyspnea (shortness of breath).
    • Palliative radiotherapy can also be given to other parts of the body to relieve symptoms caused by the spread of the cancer to the brain or bones.
  • Radiotherapy integrated with chemotherapy may be appropriate for some patients with advanced but not widespread lung cancer.
  • It can also be given in addition to surgery.
  • In certain circumstances, internal radiotherapy (brachytherapy) can be useful but it is not generally used to try to cure lung cancer. It can be useful to relieve symptoms.
Chemotherapy
  • For small cell (oat cell) carcinoma, chemotherapy is the treatment of choice. This may be combined with radiotherapy depending on the stage of the disease.
  • For Stage II and IIIA non-small cell lung cancer (NSCLC), post-surgery chemotherapy may be recommended.
  • For later stage non-small cell lung cancer, chemotherapy is still an option. It may be combined with radiation therapy and surgery.
  • Chemotherapy can be used to help with symptom control, to improve the quality of life and to show a gain in survival time. However, widespread disease cannot be cured with drug therapy.
Laser Therapy
  • Laser therapy can be used to open the airways when they are blocked by a tumour.
Photodynamic Therapy (PDT)
  • This treatment is also known as photochemotherapy or photoradiation therapy. PDT is the use of drugs that are sensitive to light (photo-sensitizing drugs). After being injected into the patient, these drugs become active and kill cancer cells only when the red light from a laser shines on them. The red laser is brought to the tumour area using a bronchoscope. When the red laser light hits the cells, it activates the drug which causes the cancer cells to die over the next 24 - 48 hours.
  • PDT is used very rarely in B.C. because special precautions must be taken by patients after being injected. They must avoid the sun and excessive bright lights for up to six weeks after treatment.
Follow Up
  • All successfully treated patients should try to stop smoking because smokers are more likely to have a second lung cancer.
  • If lung cancer returns it is usually not curable. Any treatment offered is palliative, to improve symptoms or to improve the quality and/or the quantity of life.

Follow-up after Treatment

  • Guidelines for follow-up after treatment are covered on our website.
  • You will be returned to the care of your family doctor or specialist for regular follow-up. If you do not have a family physician, please discuss this with your BC Cancer Agency oncologist or nurse.
  • Follow-up testing is based on your type of cancer and your individual circumstances.
  • Life after Cancer focuses on the issues that cancer survivors can face.
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