Metastatic Stage 4 Lung Cancer

January 24, 2025

This page was reviewed under our medical and editorial policy by Jyoti Malhotra, M.D., M.P.H., associate professor, Department of Medical Oncology & Therapeutics Research, City of Hope^® Orange County Lennar Foundation Cancer Center; and Jae Y. Kim, M.D., associate professor, Division of Thoracic Surgery, Department of Surgery, City of Hope Cancer Center Duarte

During the lung cancer diagnosis process, patients may get information about the stage of their cancer. This is a way of categorizing how large a tumor is, if the cancer has spread to lymph nodes and where else cancer may have spread in the body. Knowing the stage of the cancer helps the care team and patient plan treatment. 

Stage 4 lung cancer has spread beyond the lung and may also be called advanced or metastatic lung cancer.

What Is Stage 4 Lung Cancer?

Stage 4 lung cancer is when cancer starts in one of the lungs and then spreads to other areas, such as lymph nodes or other organs, through the blood or lymph system. It may cause symptoms as the tumor grows or cancer cells spread to impact other organs, such as the bones or liver. Treatment of Stage 4 lung cancer may sometimes reduce tumor size, relieve symptoms and help people live longer.

Stage 4 Small Cell Lung Cancer

Small cell lung cancer is divided into two stages and does not have a true Stage 4 like non-small cell lung cancer does. These stages still describe where the cancer is and how much it has spread.

The two stages of small cell lung cancer are limited-stage and extensive-stage.

Limited-stage: Cancer is found in the lung where the tumor started. It may have also spread to the lymph nodes above the collarbone or into the space between the lungs, but not beyond.

Extensive-stage: Cancer is found beyond the boundaries of the limited-stage description, possibly having reached distant sites in the body.

Stage 4 Non-Small Cell Lung Cancer

Stage 4 non-small cell lung cancer is broken into two substages that help provide a more specific description of where the cancer has spread.

Stage 4a Non-Small Cell Lung Cancer

Non-small cell lung cancer is categorized as Stage 4a if any of the following are true:

• Cancer has reached the other lung
• The fluid around the lungs has been found to contain cancer cells (malignant pleural effusion)
• The fluid around the heart has cancer cells (malignant pericardial effusion)
• The lining around the lungs (pleura) or that around the heart (pericardium) has been found to have cancer cells
• Or if cancer has been found in a distant lymph node or organ, such as the brain, liver or bones, after spreading as a single tumor

Stage 4b Non-Small Cell Lung Cancer

Non-small cell lung cancer is categorized as Stage 4b if:

• The tumor of any size has possibly grown into nearby structures
• Cancer has possibly spread to nearby lymph nodes
• Cancer has spread beyond the chest to other organs, such as the brain, bones or liver, or to distant lymph nodes

Where Does Lung Cancer Spread?

Some types of cancers tend to follow patterns as they spread. Primary lung cancer may spread to the adrenal glands (two glands that sit above the kidney and below the lung on each side), liver or to the other lung.

The way lung cancer spreads may also result in metastasis to the brain. The bones are another place cancer may spread, with lung cancer metastasis to the bone most often starting in the spine. Bone metastasis may also be found in the ribs, hip (pelvis), upper leg (femur), upper arm (humerus) or the skull.

Stage 4 Lung Cancer Symptoms

Most lung cancer cases are diagnosed after the cancer has spread outside of the lungs, so symptoms may be related to the cancer in the lungs or places to which it has spread.

Some common symptoms related to cancer in the lungs may include:

• Coughing
• Chest pain that especially hurts during coughing, laughing or breathing deeply
• Trouble breathing
• Hoarseness
• Respiratory infections (such as pneumonia) that keep coming back or do not go away completely

Symptoms may also be caused by cancer that has traveled to other organs. When cancer reaches these areas, symptoms may include:

• Jaundice (yellowing) of the skin and eyes and/or swelling in the abdomen when cancer spreads to the liver
• Bone pain or fractures in places where the cancer has spread (in the back or hips, for example)
• Memory problems, headaches, sleepiness, dizziness, seizures, or numbness or weakness in an arm or a leg when cancer spreads to the brain
• Swelling in lymph nodes where cancer has spread, such as those near the collarbone or neck

Metastasis to the adrenal gland does not tend to have symptoms, but there may be pain in the abdomen or back if the tumor is large or growing quickly.

Diagnostic Testing

Chest X-rays and different types of biopsies are often used during the diagnostic process.

Some tests are especially helpful to see if cancer has spread, which helps doctors determine the stage of the cancer. These include the following.

Computed tomography (CT) scan: An imaging test that combines multiple X-rays for a more detailed image of the area.

Magnetic resonance imaging (MRI): A test that creates detailed images using radio waves that is often used to check for cancer spread to the liver, spinal cord or brain.

Positron emission tomography/computed tomography (PET/CT) scan: A radioactive sugar injected into the blood collects primarily in cancer cells, and this combined scan gives doctors a detailed view of areas that may have cancer. It is typically not used to view the brain or spinal cord, but it may be used for most other areas in the body.

Bone scan: A small amount of radioactive material injected into the blood collects in abnormal areas of bone.

Thoracentesis: Fluid buildup around the lungs is removed and tested for the presence of cancer cells.

Thoracoscopy: A thin tube inserted between the ribs enables a doctor to examine the space inside the chest and obtain tissue samples to check for cancer cells.

Stage 4 Lung Cancer Treatment

Various treatment options are available for extensive-stage small cell lung cancer and Stage 4 non-small cell lung cancer, depending on where cancer has spread, specific genetic mutations and the patient’s overall health.

In many cases, the goal of Stage 4 cancer treatment is to relieve symptoms and improve the patient’s quality of life. This is known as palliative care.

Chemotherapy: Chemotherapy treatment for advanced lung cancer is typically given intravenously. It may be injected or given as an infusion over a longer period of time.

Extensive-stage small cell lung cancer may be treated with combination chemotherapy, which involves more than one chemotherapy drug used together. Combination chemotherapy may also be used along with immunotherapy drugs.

Stage 4b non-small cell lung cancer may be treated with chemotherapy if it has spread to other organs, such as the liver, adrenal gland or bones. Lung cancer chemotherapy may also be paired with a targeted therapy drug.

Radiation Therapy:  Extensive-stage small cell lung cancer and Stage 4 non-small cell lung cancer may be treated with radiation therapy that targets either the primary tumor or the part of the body where cancer has spread, such as the brain or bones, in order to reduce symptoms or prevent the cancer from continuing to spread.

Targeted Therapy: For Stage 4b non-small cell lung cancer that has spread widely, genetic testing may identify changes (mutations) in genes like KRAS, EGFR, BRAF and ALK. If mutations are found, targeted therapy drugs may be the first line of treatment. These drugs may help slow or stop cancer growth by focusing on specific genetic changes within cancer cells.

Immunotherapy: Extensive-stage small cell and Stage 4b non-small cell lung cancer with high levels of the PD-L1 protein may be treated with immunotherapy drugs, which boost the immune system to fight cancer cells. Immunotherapy for lung cancer might be used alone or with chemotherapy, depending on the specific characteristics of the tumor.

Surgery: Surgery may be a treatment option for Stage 4a non-small cell lung cancer in order to remove cancer from the lung, or from an organ where it has spread, such as the brain. It is rarely used to treat extensive-stage small cell lung cancer.

Other Procedures

These treatment options may help reduce symptoms caused by cancer that has spread, but additional palliative procedures may also provide relief.

For shortness of breath caused by fluid buildup around the lung, potential treatments may include the following.

Thoracentesis: A needle is inserted through the back to drain fluid around the lungs, often guided by ultrasound.

Pleurodesis: A chemical or surgical method fuses the lung lining to the chest wall, preventing fluid buildup.

Catheter placement: A tube is inserted into the chest, allowing fluid to be drained regularly from the area around the lungs.

For heart problems caused by fluid buildup around the heart, potential treatment may include the following. 

Pericardiocentesis: A needle, guided by ultrasound, is used to drain fluid from the sac around the heart (pericardium).

Creating a pericardial window: A piece of the pericardium is removed to allow fluid to drain continuously into the chest or belly, reducing the likelihood of a buildup around the heart.

For an airway that is partially blocked by the tumor, potential treatment may include the following.

Photodynamic therapy: A drug that collects in cancer cells is activated by laser light to destroy tumor cells in the airways, helping to open them up.

Laser therapy: A laser is used to burn away tumors blocking airways, often performed through a thin, tubular instrument called a bronchoscope.

Stent placement: A hard tube called a stent is inserted into an airway through a bronchoscope to keep the airway open after tumor removal or other treatments.

In addition to these lung cancer treatments, clinical trials offer access to new drugs and experimental therapies. Participating in clinical trials may provide patients additional options, especially as new treatments continue to evolve.

Stage 4 Lung Cancer Survival Rate

Cancer survival rates are based on the percentage of people with the same type and stage of cancer who were alive five years after they were diagnosed. They do not reflect what might happen for any one person, but they do offer general estimates of life expectancy. Survival rates may change across time as new treatments are identified through clinical trials.

The five-year relative survival rate for lung cancer that has spread to distant parts of the body, such as the bones, brain or liver, is 8.9%, according to the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) Program. This means that nearly 9% of patients with Stage 4 lung cancer are expected to be alive five years or longer after diagnosis, compared to those without that cancer type.

It’s important to talk to the care team to receive a personalized prognosis tailored to the patient’s type and subtype of cancer.