When cancer develops, it typically forms in one area or organ of the body. This area is known as the primary site. Unlike other cells in the body, cancer cells can break away from the primary site and travel to other parts of the body.

Cancer cells can move in the body through the bloodstream or the lymph system. The lymph system is made up of vessels that carry fluids and support the immune system. When cancer cells travel to other organs in the body, it’s called metastasis.

Cancer that metastasizes to the lungs from other areas is a life-threatening condition that develops when cancer in another area of the body spreads to the lung. Cancer that develops at any primary site can form metastatic tumors.

These tumors are capable of spreading to the lungs. Primary tumors that commonly spread to the lungs include:

If the primary site of your cancer is in the lungs, the cancer commonly spreads to the following areas:

  • the other lung
  • adrenal glands
  • lymph nodes
  • bones
  • brain
  • liver

Although less common, lung metastases can also spread to the stomach, intestines, pancreas, and kidneys.

Metastatic cancers take the name of the primary cancer instead of the name of the organ they’ve spread to. For instance, if you have lung cancer, but it has metastasized to the brain, it would still be called lung cancer.

Second primary cancer refers to a second type of cancer in a different primary site. A second primary cancer can occur at the same time or be identified later.

For cancer cells to metastasize, they must go through several changes. First, the cells have to break away from the primary site and find a way to enter the bloodstream or lymph system.

Once they’re in the bloodstream or lymph system, the cancer cells can form a new tumor in another part of the body. In the case of lung metastases, the cancer cells travel to the lungs and form a new tumor.

When the cells arrive at the lung, they’ll need to change again in order to grow in the new location. The cells must also be able to survive attacks from the immune system.

Lung metastases don’t always cause symptoms. When symptoms do develop, they can be difficult to identify. This is because the symptoms may be similar to health conditions other than cancer.

The symptoms of lung metastases can include:

Your doctor will perform a physical exam and order various diagnostic tests if metastatic cancer is suspected.

Your doctor will confirm your diagnosis by using a diagnostic test, such as:

  • Chest X-ray. This test creates detailed images of the lung.
  • CT scan. This test produces clear, cross-sectional pictures of the lung.
  • Lung needle biopsy. Your doctor removes a small sample of lung tissue for analysis.
  • Bronchoscopy. Your doctor can directly visualize all the structures that make up your respiratory system, including the lungs, with a tiny camera and light.

The goal of treatment is to control the growth of the cancer or to relieve any symptoms. There are numerous different treatments available. Your specific treatment plan will depend on various factors, including:

  • your age
  • your overall health
  • your medical history
  • type of primary tumor
  • location of the tumor
  • size of the tumor
  • number of tumors

Chemotherapy is often used to treat lung metastases. This drug therapy helps destroy cancerous cells in the body. It’s the preferred treatment option when the cancer is more advanced and has spread to other organs in the body.

In some cases, surgery may also be performed to remove the metastatic tumors in the lung. This is usually done if someone already had their primary tumor removed or if the cancer has only spread to limited areas of the lung.

Your doctor may also recommend:

Experimental treatments for metastatic cancer are also available. Heat probes can be used to destroy cancer cells in the lungs. Chemotherapy drugs may also be applied directly to the affected area of the lung containing the metastatic tumor.

You can also find clinical trials in your area at ClinicalTrials.gov.

Your long-term outlook will depend on the size and location of your primary tumor. It’ll also depend on how much the cancer has spread. Certain cancers that spread to the lungs can be very treatable with chemotherapy.

Primary tumors in the kidney, colon, or bladder that spread to the lungs may sometimes be completely removed with surgery.

In most cases, metastatic cancer can’t be cured. However, treatments may help prolong your life and improve the quality of your life.

It’s very difficult to prevent lung metastases. Researchers are working on preventive treatments, but nothing is common practice yet.

One step toward preventing metastatic cancer is prompt and successful treatment of your primary cancer.

It’s important to have a strong support network that can help you deal with any stress and anxiety you may be feeling.

You may want to speak with a counselor or join a cancer support group where you can discuss your concerns with others who can relate to what you’re going through. Ask your doctor about support groups in your area.

The National Cancer Institute and American Cancer Society websites also offer resources and information on support groups.