Chemotherapy and lung damage

Some cancer treatments can, but it is uncommon. The main effect is inflammation of the lung tissue, sometimes called pneumonitis, which can later lead to scarring if it is not treated. The medicines most often linked with it are bleomycin, used for some lymphomas and testicular cancers, and less often gemcitabine, methotrexate, busulfan, some targeted tablets, and immunotherapy. Radiotherapy to the chest adds to the risk, especially when given alongside or after these medicines.

The key signs are a new dry cough and breathlessness, first on exertion and then at rest, sometimes with a low fever and tiredness. Because the same symptoms can come from infection, blood clots, heart problems or a low haemoglobin, they always need prompt assessment. Treatment-related lung inflammation often improves when the medicine is stopped and steroids are given, and the earlier it is treated, the better the chance of full recovery. Scarring that has already formed usually does not reverse.

It can start weeks or months later

Lung effects can begin during treatment or some time after a course has finished.

Smoking increases the risk

Smoking, existing lung disease, older age and kidney problems can all raise the chance of lung effects.

Breathing tests may be done

People having bleomycin may have breathing tests before and during treatment.

It cannot tell you whether your cough or breathlessness is caused by treatment. Infection, clots, heart problems, fluid around the lungs and low haemoglobin are more common causes, and tests such as a chest X-ray, CT scan, oxygen measurement and blood tests are needed.

It also cannot tell you whether to stop a medicine. If lung inflammation is found, your oncologist may stop or pause the medicine and start steroids, and will explain whether it can be restarted.

Steroid courses need care

Steroids for lung inflammation are often reduced slowly. Never stop them suddenly, and report high blood sugar, mood changes or signs of infection.

Recovery takes time

Breathing may improve over weeks to months. Pulmonary rehabilitation and gentle exercise can help rebuild stamina.

Scarring may be lasting

If scarring develops, some breathlessness may persist. A lung specialist can advise on management.

Vaccines protect the lungs

Ask your team about flu, pneumonia and Covid vaccines, and when they can be given safely.

Air pollution matters

On high pollution days, stay indoors where possible and avoid exercising near busy roads.

Pulse oximeters are a guide only

Home oxygen readings can help, but a normal reading does not rule out a problem if you feel breathless.

Existing lung disease needs a plan

If you have asthma, COPD or previous tuberculosis, tell your team so they can plan treatment and monitoring.

Breathing exercises can help recovery

A physiotherapist can teach breathing control, pacing and positions that ease breathlessness. These techniques help during recovery and make daily activities less tiring.

Plan activity around your breathing

Break tasks into smaller steps, sit to wash or dress, keep frequently used items within reach, and rest before you become very breathless.

Tell your team about existing inhalers

If you already use inhalers, keep taking them and tell your team. They may review your lung treatment alongside your cancer plan.

Keep a breathing diary

Note each day how far you walked, whether you needed to stop, and whether you coughed at night. Small changes over a week are easier to see in writing and help your team judge whether symptoms are improving or getting worse.

Sleep propped up if breathless

Extra pillows or raising the head of the bed can make breathing easier at night. Tell your team if you can only sleep sitting up, as this needs checking.

Oxygen at home needs safety steps

If home oxygen is prescribed, keep it away from flames, gas stoves, incense and smoking. Use it exactly as advised and ask how to clean the tubing and mask.

Humid heat and cold air can both trigger coughing

Very hot, humid weather and cold, dry air from air conditioning can make breathing harder. A fan, moderate cooling and avoiding sudden temperature changes may help.

What to do next

Ask whether your treatment can affect your lungs and whether breathing tests are planned. Stop smoking, report a new dry cough or breathlessness the same day, seek emergency help for severe symptoms, and tell future doctors if you have had bleomycin.