Whether you’ve been diagnosed with metastatic (stage 4) breast cancer or you’re worried your early-stage breast cancer might progress or return, it’s important to be aware that the lungs are a common site for breast cancer to metastasize (spread).

“I finally had a lung biopsy, and the tumors lit up like a Christmas tree,” wrote one MyBCTeam member. “It’s still considered breast cancer, but it’s spread to both lungs and the lining of the lungs.”

What Raises the Risk for Lung Metastasis?

Among people diagnosed with metastatic breast cancer, about 60 percent have metastases (small tumors at a distant location) in their lungs or bones. People with more aggressive subtypes of breast cancer — like triple-negative breast cancer (TNBC) — have a higher risk of developing lung metastases. Up to 40 percent of breast cancers that have spread to the lung are TNBC.

Potential Symptoms of Lung Metastasis in Breast Cancer

Lung metastasis may not cause symptoms. If you do notice symptoms that may be associated with lung metastasis of breast cancer, don’t panic, but report them to your breast cancer care team right away. Your doctor can rule out or diagnose lung metastasis and ensure you receive proper treatment.

Here are four potential symptoms of lung metastasis to be aware of.

1. Coughing

Coughing is common with lung metastases and can occur with or without blood. Coughing without blood is also a common symptom for plenty of other conditions — such as the flu or other upper-respiratory infections. If you have severe or prolonged coughing or are coughing up blood, get medical care right away because it could indicate a serious health condition.

2. Chest Pain

Sometimes, lung metastasis causes chest pain. As with coughing, chest pain can also be caused by other health conditions ranging from relatively mild, such as asthma, to life-threatening, such as a heart attack. Be sure to call your doctor right away if you experience this symptom.

Keep in mind that if you’ve undergone or undergo radiation as part of your breast cancer treatment, you may be more likely to later develop other conditions that could cause chest pain, including:

• Pneumonitis (lung inflammation)
• Lung fibrosis (scarring)
• Lung cancer separate from breast cancer

3. Shortness of Breath

Feeling short of breath (with or without coughing) may indicate that your breast cancer has spread to your lungs. Cancer cells can spread to a part of your lungs called the pleura. This is a small fluid-filled lining that helps your lungs expand and contract when you breathe. Cancer-cell growth within the pleural space can cause an excess buildup of fluid called pleural effusion. This keeps your lungs from fully expanding and can make it harder to breathe.

Cancer in general is the third most common cause of pleural effusion. Pleural effusion caused by cancer is called “malignant pleural effusion.” Other causes could be heart failure or pneumonia (an infection in the lungs). Call your doctor so they can rule out any other potential causes of fluid buildup or difficulty breathing.

Breathlessness can also be completely unrelated to cancer. It can be caused by other conditions like:

• Pneumonia
• Chronic obstructive pulmonary disease (COPD)
• Congestive heart failure

If you’re experiencing shortness of breath, make sure to tell your doctor so they can rule out any other potential causes.

4. Wheezing

Breast cancer metastasis to the lung may cause wheezing. However, wheezing can also be a common symptom of asthma, COPD, postnasal drip due to allergies, or respiratory infections. Still, it’s best to report this symptom to your oncologist if you notice it.

Treating Breast Cancer That’s Spread to the Lungs

When breast cancer spreads to the lungs or other parts of the body, it’s more difficult to treat than other types of breast cancer. The type of treatment options your doctor may recommend will depend on the particular type of breast cancer you have.

Any stage 4 breast cancers that have metastasized to the lungs or other areas are more aggressive. In one large-scale study, people with lung metastasis had a median overall survival rate between 21 and 25 months. This means half of the people with lung metastases in the study were alive 21 to 25 months after being diagnosed. Because of this outlook, an aggressive treatment approach is usually recommended.

Generally, your doctor will recommend systemic therapy — medications that will treat cancer cells anywhere in your body. That way, they can target the cancer in your breast tissue and lungs.

Your doctor may recommend radiation therapy, but if your breast cancer has metastasized, radiation in the breast tissue alone usually isn’t enough to kill the cancer that has spread. They may also recommend surgery if there’s only a small number of lung metastases — so long as your main breast cancer is under control.

Chemotherapy Treatments

A significant portion of people with lung metastases have triple-negative breast cancer. This type of breast cancer is usually treated with chemotherapy, a nonspecific medicine that kills rapidly dividing cells, such as cancer cells. People with other types of breast cancer can also be treated with chemotherapy or other, more specific therapies for cancer that isn’t TNBC.

Hormone Therapies and Targeted Treatments

If you have hormone receptor-positive (HR-positive) breast cancer — in which cancer cells have either the estrogen receptor (ER) or the progesterone receptor (PR) — your doctor may recommend hormone therapy. Hormone therapy will only work if you have ER-positive or PR-positive breast cancer.

If your breast cancer cells are positive for human epidermal growth factor receptor 2 (HER2), your doctor may recommend targeted therapies that identify this protein and attack cells carrying it. For instance, the drug trastuzumab (Herceptin) will specifically target cancer cells that express HER2 on the cancer cell surface. The drug pertuzumab (Perjeta) also targets HER2-positive breast cancer. If your breast cancer cells are negative for HER2, your doctor may prescribe a targeted therapy such as ribociclib (Kisqali).

Immunotherapy

Immunotherapies are a newer type of cancer treatment that help a person’s immune system better fight cancer cells.

If you have TNBC, your doctor may prescribe chemotherapy with an immunotherapy drug called pembrolizumab (Keytruda). Pembrolizumab helps activate the immune response against breast cancer cells.

More effective treatments for metastatic breast cancer are under development. There are also many clinical trials that are studying better treatment options for people with metastatic breast cancer.

Treating Symptoms of Lung Metastasis

Metastatic breast cancer is often considered incurable. Therefore, metastatic breast cancer treatment is focused on improving your quality of life and reducing your symptoms. This type of treatment is known as palliative care.

Shortness of breath can be one of the most challenging symptoms of lung metastasis. Your doctor may prescribe strong pain relievers like opioids to decrease the feeling of shortness of breath. They can also prescribe anti-anxiety medications to help you with anxious thoughts or panic due to having trouble breathing.

Your doctor can also prescribe medicines specifically for fluid in the lungs. Sometimes, if fluid is causing symptoms, it could be due to an infection. Your doctor can prescribe antibiotics and drain the excess fluid through a small tube.

Together, your oncology team will give you the best combination of cancer-killing medicine and treatments to help manage your symptoms and improve your quality of life.

Talk With Others Who Understand

On MyBCTeam — the social network for people with breast cancer and their loved ones — more than 67,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Have you received a metastatic breast cancer diagnosis? Or are you experiencing lung symptoms you’re worried may indicate that your breast cancer is spreading? Share your experiences in the comments below, or start a conversation by posting on your Activities page.