Metastatic lung cancer is cancer that begins in the lungs and spreads to other areas. By the time lung cancer reaches metastasis, it is late stage and can be hard to treat, but outcomes vary between people.

Lung cancer often has no symptoms in its early stages.

According to a 2015 study, in approximately 30–40% of people with non-small cell lung cancer, the cancer had metastasized by the time it was diagnosed.

“Metastatic” refers to a stage, not a form of cancer. The name of cancer does not change when the disease affects a new area. For example, lung cancer that spreads to the liver is called metastatic lung cancer, not liver cancer.

This article looks at how lung cancer spreads to other organs, the effects on the body, and how doctors treat it.

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Metastatic cancer has spread from one area of the body to another. For example, if cancer affects the bones of a person with lung cancer, it may have spread from the lungs to the bones. This is called metastatic lung cancer.

Metastatic lung cancer cells have the same features as the original lung cancer cells. A healthcare specialist called a pathologist can see this if they examine the cancerous tissue under a microscope.

Sometimes, however, doctors do not diagnose cancer before it spreads, and it is not possible to identify where it first developed.

In other cases, a person receives treatment for cancer in one area, and then their cancer spreads, becoming metastatic, after several years. This can occur even if tests no longer detect the original tumor.

Lung cancer may develop again in the same lung after successful treatment. This is called recurrent lung cancer.

If cancer develops in the other lung, it is metastatic if it has spread. Or it may be a new, separate case of lung cancer.

Metastatic cancer does not always cause symptoms. If they occur, the specific type of symptom depends on the affected body area.

Below, learn about areas that metastatic lung cancer commonly affects and some symptoms that may arise.

Adrenal glands

If cancer has spread to the adrenal glands, it usually causes no symptoms. However, if the tumor is large, it may cause pain in the back or abdomen.

If cancer affects at least 90% of both glands, it can cause adrenal insufficiency. This can lead to symptoms such as:

Bones

Around 35–40% of people with advanced lung cancer develop bone metastases. In this case, pain is the main symptom. The risk of fractures increases.

Brain

About 40% of people with non-small cell lung cancer develop brain metastases. Symptoms include:

Liver

Symptoms of metastatic lung cancer to the liver include:

  • abdominal pain
  • fatigue
  • nausea
  • jaundice, which is the yellowing of the skin and the whites of the eyes

Lymph nodes

Enlarged lymph nodes in the armpit, neck, and stomach can suggest that lung cancer has spread.

However, these nodes also swell in response to other health issues.

Most cells have a limited life cycle. As they die, new ones form.

Lung cancer cells do not behave in this typical manner. They develop when cells in the lungs continue to multiply without dying.

The excess cells form a tumor. As the tumor grows, it needs more space, and it starts spreading to other areas. At this point, the cancer becomes metastatic.

Cancer cells spread in two ways, either by:

  • entering nearby tissue
  • breaking away from the tumor and traveling through the bloodstream or lymphatic system to other parts of the body

The National Cancer Institute notes that cancer cells can:

  • grow on or into nearby tissue and form a new tumor
  • move through the walls of nearby blood vessels
  • stop inside blood vessels
  • increase the growth of blood vessels, which supply additional blood and oxygen to the tumor

Where does it spread?

If lung cancer spreads, it typically invades areas such as the:

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

Testing for metastases involves checking the areas where lung cancer typically spreads.

Diagnostic testing involves:

Cancer that has metastasized throughout the body can be difficult to eliminate. Therefore, treatment focuses on controlling the growth of cancer and relieving symptoms.

The treatment options depend on the type of lung cancer, the location of the metastases, previous treatment, and the person’s overall health.

Options include:

Preventing metastasis

Some cancer treatments may help stop or slow metastasis by making conditions less suitable for the growth of cancer cells.

Anti-angiogenic drugs, for example, can stop tumors from growing their own blood vessels. Cutting off the supply of blood to the tumor can slow or prevent its growth.

Tyrosine kinase inhibitors (TKIs) prevent or reduce tumor growth by blocking growth signals within or between cancerous cells.

Meanwhile, scientists are investigating other ways to prevent cancer from spreading.

Healthy cells contain adhesion molecules that allow them to stick together. A 2019 study suggests that the loss of function in adhesion molecules may contribute to metastasis.

Scientists have also discovered that cancer cells secrete substances called exosomes that stimulate the cells to move. Research into the role of these exosomes in metastasis is ongoing.

It is not always possible to prevent lung cancer or keep it from spreading.

However, avoiding things that increase the risk of developing lung cancer can help. Smoking, for example, is a preventable risk factor.

Also, treatment is more likely to be effective in the early stages. Receiving a diagnosis and treatment early may prevent the cancer from spreading.

However, receiving an early diagnosis can be challenging because there are often no symptoms in the early stages. This is why screening is so important: It can detect lung cancer when treatment may be more successful.

People with a high risk of lung cancer may wish to consider screening. It may be appropriate for people who:

  • are 50–80 years old
  • currently smoke or stopped smoking in the last 15 years
  • have smoked a pack a day for 20 years, two packs a day for 10 years, or the equivalent

Screening can help detect changes early when effective treatment can reduce or eliminate the cancerous cells before they spread.

The American Lung Association offers useful resources about accessing a lung cancer screening.

What is the life expectancy of metastasized lung cancer?

According to the American Cancer Society, people with non-small cell lung cancer that has spread to distant areas have a 9% chance of surviving another 5 years after diagnosis compared with people who do not have the cancer.

For those with small cell lung cancer that has spread to distant areas of the body, this figure is around 3%.

Treatments can help manage symptoms and improve a person’s quality of life. In some cases, treatments may also slow the development of the cancer and help extend the person’s life.

Does metastatic lung cancer mean terminal?

Metastatic lung cancer is also known as advanced lung cancer.

Advanced cancer cannot usually be cured. Therefore, it is considered a terminal illness.

However, treatment might control it, help relieve symptoms, and improve a person’s quality of life for some time.

What are the first signs of metastatic lung cancer?

Possible first symptoms of metastatic lung cancer include:

  • a new cough or a cough most of the time
  • breathlessness
  • unexplained weight loss
  • ongoing chest infections
  • coughing up blood
  • a hoarse voice
  • difficulty swallowing

Treatments and lifestyle adjustments can help enhance the comfort and quality of life of someone with metastatic lung cancer.

The support of friends, family, and healthcare professionals can help a person manage the emotional effects and practical challenges of living with cancer.

Specifically, a person may benefit from:

  • seeking support from friends and family
  • joining a cancer support group
  • attending counseling
  • regularly discussing symptoms and options with members of their healthcare team

A healthcare professional can often help locate appropriate counseling services and support groups.

In addition, the American Lung Association provides a directory of support groups and other resources.