How Stage 4 Breast Cancer Can Lead to Pneumonia

How Stage 4 Breast Cancer Can Lead to Pneumonia


For a healthy individual, pneumonia can be a difficult condition to treat. For a person with advanced breast cancer who may be undergoing treatments that further weaken the body’s ability to fight infection, pneumonia can be particularly serious. In addition, some breast cancer treatments can increase your risk for pneumonia.

What is pneumonia?

Pneumonia is an infection of the air sacs in your lungs. The infection causes inflammation (swelling) of the lung tissue and can affect breathing and oxygen exchange. These infections are most commonly caused by bacteria, but can also be caused by viruses or fungi. Pneumonia can affect one or both lungs.

Pneumonia causes different symptoms based on patient factors and what germ or bug is causing the infection. Severity of symptoms can range from mild to life-threatening. Many of pneumonia’s symptoms are similar to other less serious respiratory infections.

Symptoms of pneumonia

Symptoms of pneumonia include:

  • fever
  • discomfort
  • chills or sweating
  • a cough that produces a thick, sticky fluid
  • diarrhea
  • nausea
  • vomiting
  • muscle fatigue
  • chest pain
  • muscle aches
  • fatigue

Pneumonia and cancer

Advanced cancer, such as stage 4 cancer, weakens the immune system, which increases your risk of developing infections including those that cause pneumonia. People with cancer also have a hard time fighting the infection because of their body’s compromised state.

In stage 4 breast cancer, cancer cells have invaded other organs in the body. This is also called metastatic cancer. People with this stage of cancer may be facing declining health and limited life expectancy. Three factors can contribute to pneumonia in people with late-stage breast cancer, including:


Breast cancer stages describe how advanced the breast cancer is or how far it has spread. Stage 4 breast cancer means the breast cancer has spread beyond the breasts. Once the cancer cells reach the lymph nodes, the cancer may spread to more distant sites like the bones, lungs, liver, or brain.

If cancer spreads to the lungs, it may affect the lung’s ability to function. Fluids and pneumonia-causing organisms can get trapped in the lungs and make breathing harder.

Pneumonia as a post-operation complication

People with breast cancer may undergo surgery in an effort to remove the cancer or treat complications related to it. Unfortunately, surgery puts an extra burden on an already fragile body. People with breast cancer who have surgery can develop pneumonia several weeks or months afterward. This is a very rare complication.

Radiation treatment

Radiation treatment to breasts or nearby tissue and bones can increase your risk for a condition called cryptogenic organizing pneumonia (COP), formerly called bronchiolitis obliterans organizing pneumonia. Radiation treatments may lead to COP, though this is rare. Symptoms include coughing, shortness of breath, and fever.

Treating pneumonia

Pneumonia in stage 4 breast cancer can be treated, but cancer patients have a weakened immune system so they are at a higher risk of complications and may need to be hospitalized for treatment.

Common treatments for pneumonia include:

  • antibiotics, to treat pneumonia caused by bacteria (several types of bacteria can cause pneumonia, so your doctor will need to conduct tests to determine the type of antibiotic you need)
  • antifungal medicines, to treat pneumonia caused by a fungal infection
  • viral pneumonia is usually treated with supportive measures like fluids, oxygen if needed, as well as medicines that help relieve the symptoms of pneumonia like fever and cough
  • cough medicine, to help relieve this common symptom, and over-the-counter medicine such as ibuprofen and aspirin to reduce fever and discomfort associated with pneumonia

Some patients can be treated with oral medications at home but others will need to be admitted to the hospital for IV medications.

Identifying pneumonia

Advanced-stage breast cancer causes a variety of symptoms and possible health complications. With so many changes taking place in your body, understanding the causes and symptoms of pneumonia is important. Breast cancer patients have a weakened immune system and infections like pneumonia can be life-threatening. If you are experiencing symptoms of pneumonia, contact your doctor right away.

Read This Next

Does Having Dense Breasts Increase Your Risk for Cancer?
Managing Pain Associated with Breast Cancer
Tips for Family and Caregivers
What to Ask Your Doctor About Breast Cancer
Breast Cancer Questions and Answers