When cancer starts in the lungs and then spreads to a distant organ, it’s called metastatic lung cancer. Lung cancer is the primary cancer. Metastatic lung cancer is also called stage 4 lung cancer.
There are two main types of lung cancer. About 85 percent of lung cancers are non-small cell lung cancer (NSCLC). NSCLC is further divided into adenocarcinoma, squamous cell, or large cell. These distinctions are based on how the cells look under a microscope. About 15 percent of lung cancers are a faster-growing type called small cell lung cancer (SCLC).
Other rare types of lung cancer include mesothelioma and carcinoid tumors.
There are four stages of NSCLC:
- Stage 1 NSCLC is found in one area or lobe of the lung and the tumor is less than 3 centimeters.
- Stage 2 NSCLC is in one area or lobe of the lung and the tumor is 5 to 7 centimeters, or the tumor is 3 to 5 centimeters and cancer is in nearby lymph nodes.
- Stage 3 NSCLC has spread to the lymph nodes within in the chest or above the collarbone. Cancer may have spread to the opposite lung or lymph nodes.
- Stage 4 NSCLC has spread to both lungs. Cancer is found in the fluid around the lungs and may have spread outside the chest to distant organs.
SCLC can be staged the same way as NSCLC, using tumor size, lymph nodes, and presence or absence of distant metastases. Often, it’s staged in a more general way:
- Limited stage SCLC is found in part of one lung and nearby lymph nodes.
- Extensive stage SCLC is found in both lungs. It’s also in the fluid around the lungs, or it has spread to other areas of the chest or distant sites.
The signs and symptoms of localized lung cancer may include:
- coughing, with or without blood
- shortness of breath
- chest pain
- weight loss
As the disease progresses to nearby tissue or lymph nodes, additional signs and symptoms may include:
- trouble swallowing
- excess fluid around the lung or heart
Metastatic lung cancer can cause many more signs or symptoms, depending on where it spreads. Potential signs and symptoms can include the following:
- If it spreads to your lymph nodes, you may have lumpiness or swelling in your armpit or neck.
- If it spreads to your bones, you may have bone pain.
- If it spreads to your brain, you may have headaches, nausea, vision problems, confusion, or seizures.
- If it spreads to your liver, you may have abdominal pain or jaundice.
- If it spreads to your adrenal glands, you may have a hormonal imbalance.
Metastatic lung cancer can also lead to:
- loss of appetite
- weight loss
- generalized pain
Cancer cells are abnormal cells that keep multiplying without normal control signals. As they grow in number, they form tumors and push their way into nearby tissue. Cancer cells that enter the lymphatic system or bloodstream can end up virtually anywhere in the body.
Lung cancer tends to spread to nearby lymph nodes first. Other common sites of metastasis include the:
- adrenal glands
Diagnosis will probably require some sort of tissue sample in addition to a physical exam and blood tests. Your doctor will order additional testing based on your symptoms.
Tumors can be seen on many imaging tests such as X-ray, ultrasound, or MRI. You may also need a CT scan, PET scan, or bone scan. Which test you have will depend on the area that your doctor needs to see.
If you’re producing mucus, it can be analyzed for the presence of cancer cells. A biopsy of the actual tumor or cytology of pleural fluid is the best way to determine if cancer cells are present.
SCLC is more likely to be diagnosed when it’s in an advanced stage than when it’s in a limited stage.
Metastatic lung cancer is treated differently than early-stage lung cancer. You’ll need to discuss goals and expectations with your oncology team before you start treatment. Treating stage 4 lung cancer typically focuses on reducing symptoms and extending life while maintaining the best possible quality of life.
Treatment options will depend on areas where the cancer has spread. Other important factors include your age and overall health status.
Radiation can sometimes be used to treat specific symptoms related to the cancer. The radiation beams can be directed to specific areas. It’s often used to treat brain and bone metastasis. It may also be used to reduce symptoms in the lungs.
Chemotherapy is a type of systemic therapy. That means it can kill cancer cells throughout your body. In recent years new, targeted treatments have been approved for use in NSCLC that have greatly improved survival for people with stage 4 NSCLC.
Some of these newer drugs, such as erlotinib and crizotinib, come in pill form. Nivolumab requires an IV infusion, which means it’s given through your vein. These drugs are more effective for people with specific genetic mutations, so not everyone will benefit from each of these. Ask your doctor if any of these drugs are right for you.
If fluid had built up around your lungs, your doctor can drain it. You may also need medication to relieve pain and discomfort.
Sometimes, people have more than one type of treatment. Treatments can be given in combination or one after the other. All therapies have potential side effects. These side effects can be similar to the symptoms of the cancer. Side effects may include:
- a loss of appetite
As you see what effect treatment has on the cancer and how your body reacts, you can discuss altering your treatment plan with your doctor. Together, you can continue to discuss and identify your treatment goals and find what best suits your needs and wishes.
Clinical trials help doctors study new medications and treatments. If you’d like to participate in a clinical trial, ask your oncologist for more information.
Living with metastatic lung cancer can be overwhelming. That’s why open communication with your doctor is vital. Don’t be afraid to speak up about matters that affect your quality of life.
You may find it helpful to join a support group for people with metastatic cancer. Other organizations offer assistance with transportation, chores, financial aid, or hospice care. The American Cancer Society maintains a 24/7 National Cancer Information Center to help you locate these resources.
Cancer survival rates are estimates based on large numbers of people with a given disease. They’re based on the stage at diagnosis. According to the American Cancer Society, the five-year observed survival rate for stage 4 NSCLC is 1 percent. The five-year relative survival rate for stage 4 SCLC is 2 percent. That means that 1 to 2 percent of people diagnosed with stage 4 lung cancer will survive at least five years after diagnosis.
Many things can affect your individual outlook. Talk to your doctor to learn more about it.
Lung cancer can’t always be prevented. Some people get lung cancer even with no known risk factors.
The single most important thing you can do to reduce your risk of developing lung cancer is not smoke. If you smoke, you can still lower your risk by quitting now. It’s also a good idea to avoid exposure to other people’s smoke.
You can also have your home tested for radon exposure. If you work with cancer-causing chemicals, be sure to follow all safety regulations.
A diet rich in vegetables and fruits, along with regular physical activity, may also help lower your risk of cancer.