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Lung damage and chemotherapy

Some chemotherapy drugs can affect the lungs (pulmonary toxicity). The exact effect of chemotherapy drugs that cause lung problems is not fully known. It may be that the drugs cause inflammation in the lung cells that result in a lung infection (pneumonitis). The drugs may also cause fibrous, scar-like tissue to form in the lungs (pulmonary fibrosis) and restrict lung function.


Lung damage is often related to the dose of the drugs used. Usually, the higher the dose, the greater the lung damage. Some chemotherapy drugs that are known to cause lung damage are:

  • bleomycin (Blenoxane) – most common
    • Lung damage occurs in up to 10% of people who receive this drug.
    • The risk increases when higher doses are used.
  • carmustine (BiCNU, BCNU)
    • Lung damage occurs in about 20%–30% of people who receive high-dose therapy with this drug.
  • methotrexate
    • Pulmonary toxicity occurs in up to 8% of people who receive this drug.
  • alkylating drugs, such as cyclophosphamide (Cytoxan, Procytox) or busulfan (Busulfex)
    • Lung damage occurs in less than 1% of people who receive these drugs.

Lung damage occurs more often in people who:

  • are elderly
    • People over 70 years of age have a higher risk of developing lung problems.
  • have a personal history of lung disease
  • have received radiation therapy to the lungs or chest
  • receive combinations of chemotherapy drugs


Symptoms of lung damage include:

  • dry cough
  • shortness of breath (especially with activity)
  • wheezing
  • fatigue

Symptoms can occur during treatment with chemotherapy or a few months after treatment ends. Damage to the lung tissue is usually not reversible.


Changes to lung tissue may be detected with:

  • physical examination, including listening to the lungs (auscultation)
  • chest x-ray
  • blood tests to check the level of oxygen in the blood, such as blood gas analysis or oxygen saturation
  • tests that measure lung function, such as pulmonary function test (PFT)

Prevention and management

Since lung damage is usually not reversible, measures are taken to detect it early. If lung damage occurs, the dose of the drug may be lowered or the drug may be stopped altogether to prevent further damage.

When shortness of breath occurs, it may be treated with:

  • oxygen therapy
  • corticosteroid drugs to reduce inflammation
  • bronchodilator drugs to widen the bronchi (large tubes, or airways, in the lungs)

People can cope with shortness of breath by:

  • avoiding smoking and second-hand smoke
  • organizing and prioritizing activities
    • Pace and plan activities with rest periods or decide which activities are the most important.
  • using techniques to slow and improve breathing, such as pursed-lip breathing
    • Pursed-lip breathing is breathing in slowly through the nose, then puckering or pursing the lips and breathing out slowly and gently through the mouth.

For more detailed information on specific drugs, go to sources of drug information.


The body’s protective response to injury or infection that includes redness, swelling, pain and warmth of the affected area.

pulmonary function test (PFT)

A test used to measure how well the lungs are working, including how much air the lungs can hold, how quickly air moves in and out of the lungs, how much oxygen is taken in and how much carbon dioxide is given off.

Also called lung function test.


Any steroid hormone that acts as an anti-inflammatory by reducing swelling and lowering the body’s immune response (the immune system’s reaction to the presence of foreign substances).

Corticosteroids are made by the adrenal gland. They can also be produced in the lab.


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