Metastatic Lung Cancer

Woman with metastatic lung cancer sitting in a kayak, holding an oar, as her husband pushes the kayak into the lake on a sunny day

What is metastatic lung cancer?

Metastatic lung cancer, also known as stage 4 lung cancer, is the most advanced type of lung cancer. The term metastatic cancer means that the cancer cells have spread to distant areas in the body, away from their original location in the lung.

As this type of lung cancer has spread and affects other tissues and organs, it’s more difficult to treat than early-stage lung cancer. But you do have treatment options. Your care team will work with you to plan your next steps and improve your quality of life with metastatic lung cancer.

Where does lung cancer spread?

Over time, lung cancer cells may spread to nearby areas in the chest, nearby lymph nodes or the other lung. The cells can also eventually travel through the blood vessels or lymph system to other places in the body. When this happens, tumors may form in areas like the bones or brain.

Bones

It’s common for non-small cell cancer cells to grow outside of the lungs into the bones. It’s estimated that about 1/4 to 1/3 of people with this type of lung cancer will have metastatic lung cancer in the bones. Lung cancer often spreads to the spine, hip, ribs or thigh bones.

Brain

Lung cancer that has spread to the brain is found in both small cell lung cancer and non-small cell lung cancer cases. However, the growth rate of small cell lung cancer tends to be more rapid. Approximately 40% of individuals diagnosed with lung cancer eventually experience metastatic brain cancer.

Adrenal glands

In both small cell lung cancer and non-small lung cancer, cancer can spread to the adrenal glands. These glands make hormones and are located near the kidneys.

Liver

Liver metastases are most common in people with advanced small cell lung cancer. If you have lung cancer that has spread to your liver, your treatment plan may include procedures that deliver therapy directly to these areas of cancer.

Lymph nodes

Nearby lymph nodes are often one of the first places that lung cancer spreads, even in earlier stages of cancer. But when lung cancer cells start to spread to lymph nodes farther away from the original cancer site, then your cancer may be classified as metastatic cancer.

Other lung

Sometimes, lung cancer will spread from one lung to the other. This is more common with non-small cell lung cancer. People who have lung cancer that spreads to the other lung tend to have a better prognosis than when lung cancer spreads to distant locations in the body.

What causes metastatic lung cancer, and how does it spread?

Metastatic lung cancer develops over time. As lung cancer grows, it invades tissues near the lungs first. Eventually, these cancer cells may move into the lymphatic vessels through a lymph node or blood vessel. Through these vessels, cancer cells can travel through the body and get into other tissues. Cancer cells form a metastasis or tumor when they divide and grow in this new location.

Lung cancer metastasis and staging

Metastasis is one of three main factors used by your care team in lung cancer staging, along with the original tumor size and location and whether it has spread into lymph nodes. Understanding if you have a lung metastasis and where the cancer has spread is important to planning your next steps in treatment. For example, lung cancer that hasn’t spread or metastasized is often treated with surgery, whereas metastatic lung cancer may not be.

How is metastatic lung cancer diagnosed?

Along with tests that initially diagnose cancer, you may have blood tests to check on your overall health or imaging tests that help stage your cancer and look at how far it has spread in the body.

Medical history and physical exam

When you have symptoms of a lung condition, your doctor will review your medical history and perform a routine exam. During your exam, your doctor listens to your chest and heart and looks for any signs that might be caused by lung cancer.

Imaging tests

A chest X-ray is one of the leading imaging tests to screen and diagnose lung cancer. However, additional types of imaging tests can help your care team find signs of cancer that has spread.

Computed tomography (CT): A CT scan uses multiple X-ray images to give your doctor a more detailed look at your lungs or other body areas.
Positron emission tomography (PET): A PET scan is helpful in the diagnosis and staging of lung cancer. It uses a substance to highlight cancer cells on images, showing your doctor if and where cancer has spread in the body.
Magnetic resonance imaging (MRI): An MRI uses magnets and radio waves to create images of your body and look for signs of metastatic lung cancer. For example, you may have an MRI of your brain to see if lung cancer has spread there.
Bone scan: A bone scan is sometimes used in metastatic lung cancer diagnosis to determine if cancer has spread to the bones. Like PET scans, bone scans use a substance to highlight cancer cells.

Blood tests

Blood tests don’t diagnose metastatic lung cancer but give your care team valuable information about your overall health. They can tell your doctor how well specific organs that may be affected by cancer work.

Complete blood count (CBC): A CBC is a routine blood test that shows your general health, specifically, how many of each type of blood cell you have in your blood.
Electrolyte panel: If the levels of electrolytes in your blood, such as sodium, potassium or magnesium, are off, it might signal a kidney problem.
Liver function tests: A liver function test checks for signs that your liver isn’t working as it should.
Oxygen saturation: When you have lung cancer, it can affect your lungs and their ability to give your body enough oxygen. Oxygen saturation measures the level of oxygen found in your blood.
Tumor marker tests: Tumor marker blood tests look for specific proteins related to cancer that may be in the blood.

Bronchoscopy

Bronchoscopy is one of the main procedures for diagnosing lung cancer. It uses a thin tube with a camera attached, called an endoscope, to go through the mouth or nose and down into the airways. During a bronchoscopy, your care team can examine areas of your lungs, take biopsies or perform other procedures.

Biopsies

If your care team finds an area of concern on imaging, you may have a biopsy to confirm whether the nodule or mass is lung cancer. During a biopsy, your doctor takes tissue or fluid samples, which a pathologist reviews under a microscope to look for cancer cells.

Depending on your specific needs, there are a few different ways to take a lung biopsy. Some biopsies are taken using a hollow needle inserted through the chest. In other cases, you may need an endoscopic procedure like bronchoscopy or a surgical procedure to allow your care team to reach the area that needs to be biopsied.

Treating metastatic lung cancer

While metastatic lung cancer is more challenging to treat, you still have lung cancer treatment options to manage symptoms and improve your overall quality of life. At this stage, surgery to altogether remove your cancer is not usually part of your care plan. Treatments like chemotherapy, radiation therapy or immunotherapy are more common.

Your care team will also carry out treatments focused on relieving pain or caring for the emotional, mental or social effects of metastatic lung cancer. Your care plan will be tailored to your unique needs and goals.

Treating stage 4 NSCLC
Treating stage 4 non-small cell lung cancer depends on how far it has spread. You may still have surgery to remove specific areas of cancer, along with additional treatments. But, when cancer has spread too much in the body, your treatments are typically systemic—which means treatments that deliver cancer-fighting therapy to your entire body.

Some treatments for stage 4 NSCLC include:
- Chemotherapy uses cancer-killing drugs to fight areas of cancer throughout the body. However, including chemotherapy in your treatment plan depends on other aspects of your health.
- Radiation therapy is sometimes used with other therapies or as the primary treatment option in stage 4 NSCLC. Radiation is either targeted at cancer cells using precise external beams or delivered inside the body directly, called brachytherapy.
- For people with stage 4B NSCLC, checkpoint inhibitors, a type of immunotherapy, may help the immune system recognize and fight cancer cells.
- Several types of targeted therapies are available to treat stage 4B non-small cell lung cancer. These therapies target specific changes in the genes in your cancer cells.
Treating extensive-stage SCLC

The primary treatments for extensive-stage small cell lung cancer are chemotherapy and immunotherapy. These treatment options fight cancer throughout the body. Chemotherapy uses drugs to destroy fast-growing cancer cells, while immunotherapy helps the body recognize cancer cells so the immune system can attack them.

At this late stage of lung cancer, you also have treatment options focused on relieving pain, reducing symptoms or addressing the many physical and emotional effects of cancer, called palliative care. This type of care differs from hospice care and is used alongside other treatments. For example, one procedure to relieve symptoms in extensive-stage SCLC is thoracentesis, which removes fluid buildup around the lungs.