Stage 3 lung cancer is when cancer that started in your lung has spread to nearby lymph nodes or tissue but not to distant organs. Early diagnosis and treatment may improve your prognosis.

There are two types of lung cancer. Each type may have different prognoses.

  • Small cell lung cancer (SCLC) accounts for 10–15% of lung cancers. Most people with this type of lung cancer are diagnosed when the cancer has already spread beyond the lungs.
  • Non-small cell lung cancer (NSCLC) accounts for 80–85% of lung cancers. It typically spreads more slowly than SCLC.

Keep reading to learn more about the staging, survival rates, and outlook for stage 3 lung cancer.

Healthcare professionals use several staging methods. Stages help them see how large the tumor is and whether the cancer has spread beyond the lung.

This also helps them determine the best treatment plan.

TNM staging

For NSCLC and SCLC, the American Joint Committee on Cancer (AJCC) TNM system may be used. TNM stands for:

  • (T) Tumor: This measures the size of the tumor and whether it has spread.
  • (N) Nodes: This measures whether the tumor has spread to nearby lymph nodes.
  • (M) Metastasis: This measures whether the tumor has spread beyond the lungs to other organs.

A healthcare professional will also assign a number for each category. Then, based on their TNM analysis, they can classify the lung cancer into a numbered staging system between 0 and 4.

Numbered stages

For NSCLC, healthcare professionals may use numbered stages. Stage 0 is the earliest, while stage 4 is the most advanced stage of lung cancer.

Stage 3 lung cancer can be divided into three sub-stages:

  • 3A: This stage is considered locally advanced. The cancer has spread to the lymph nodes on the same side of the chest as the primary lung tumor, but it has not traveled to distant areas in the body.
  • 3B: The cancer has spread from the site of the primary tumor to lymph nodes above the collarbone, to the nodes on the opposite side of the chest, or to the area between the lungs or around the heart.
  • 3C: The cancer has spread to all or part of the chest wall or its inner lining, the phrenic nerve, or the membranes of the sac that surrounds the heart. Two or more separate tumor nodules in the same lobe of a lung have also spread to nearby lymph nodes but not distant parts of the body.

Limited and extensive

For SCLC staging, a two-stage system may be used:

  • Limited: The cancer affects only one side of the body, such as the lung, chest, and lymph nodes.
  • Extensive: The cancer has spread to nearby tissues and lymph nodes or to distant organs.

The American Cancer Society (ACS) calculates 5-year relative survival rates using data from the Surveillance, Epidemiology, and End Results (SEER) database.

The 5-year relative survival rate represents the likelihood that someone with a certain type or stage of cancer is alive 5 years after they were diagnosed compared with the general population.

SEER uses the following three-stage system to classify NSCLC and SCLC lung cancers:

  • Localized: Cancer has not spread beyond the lung.
  • Regional: Cancer has spread to nearby lymph nodes and tissues.
  • Distant: Cancer has spread to distant parts of the body, such as organs.

Stage 3 lung cancer is moving from the regional to the distant stage. It hasn’t yet reached distant organs, such as the brain, bones, adrenal glands, and liver.

Below are the 5-year relative survival rates for people diagnosed with NSCLC and SCLC lung cancer between 2012 and 2018:


Early detection is the best way to improve outlook.

Current screening guidelines may help reduce lung cancer deaths by 20%, according to the National Cancer Institute (NCI).

The U.S. Preventive Services Task Force recommends annual screening for lung cancer if you:

  • are 50–80 years old
  • have a 20-pack-year smoking history
  • currently smoke or quit within the last 15 years

A 20-pack-year smoking history means you have smoked 1 pack of cigarettes a day for 20 years, or 2 packs a day for 10 years.

Lung cancer screening is typically done using a low dose computed tomography test (CT scan).

Treatment for stage 3 lung cancer depends on several factors, such as:

  • the type of cancer
  • where and how far it’s spread
  • other health conditions you may have

If possible, treatment typically begins with surgery to remove as much of the tumor as possible. This may involve removing part of your lung (lobectomy) or your whole lung (pneumonectomy).

After surgery, or if surgery is not possible, a doctor may recommend:

  • chemotherapy
  • immunotherapy
  • radiation therapy
  • targeted therapy

Learn more about how to take care of yourself during lung cancer treatment.

Is Stage 3 cancer terminal?

Stage 3 lung cancer may be treatable. The 5-year relative survival rate for lung cancer has gradually been improving. The number of deaths has decreased by 20% for males and 14% for females in the past 5 years, according to the American Lung Association.

Why is Stage 3 lung cancer inoperable?

Stage 3A NSCLC lung cancer may be treated with surgery. However, SCLC and stages 3B and 3C NSCLC lung cancer may not be treated with surgery because the cancer is too widespread.

A healthcare professional can help determine the best treatment plan for you if surgery is not an option.

Speak with a doctor about any questions or concerns you may have about treatment. They will help you explore your options and develop a treatment plan that’s right for you.

Lung cancer clinical trials may offer an opportunity to participate in trialing a new treatment. These may not offer a cure, but they can potentially improve your prognosis.