Stage 3 non-small cell lung cancer has spread to nearby tissues and lymph nodes but not to more distant tissues. Most people with this stage have lung cancer symptoms. Treatment can depend on several factors.

older person with stage 3 NSCLC sitting under a blanket-1Share on Pinterest
Getty Images/Milan Markovic

Lung cancer is the second most common cancer in both males and females in the United States. The American Cancer Society estimates that 234,580 new diagnoses of lung cancer will be made in the United States in 2024.

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Researchers estimate it makes up about 85% of all lung cancer diagnoses.

After a doctor makes a lung cancer diagnosis, they determine the extent of the cancer, or its stage. Stage 3 NSCLC has spread to nearby tissues and lymph nodes but hasn’t yet spread distantly.

Learn more about non-small cell lung cancer (NSCLC).

Stage 3 NSCLC is considered to be locally advanced. This means the cancer has spread from where it started in the lung into nearby lymph nodes or tissues.

Many people with NSCLC receive a diagnosis at an advanced stage, which includes stage 3 and stage 4. A 2021 paper estimates that 20–35% of people receiving an NSCLC diagnosis have stage 3 cancer.

NSCLC is staged using the TNM system, which evaluates:

  • Tumor size (T): This is a measure of the size or extent of the tumor. Stage 3 NSCLC can be T1 through T4.
  • Lymph node spread (N): This assesses the extent of the cancer’s spread into lymph nodes. Stage 3 NSCLC can be N0 through N3.
  • Metastasis (M): This shows whether the cancer has spread to more distant tissues. All stage 3 NSCLCs are M0 (no metastasis).

Stage 3 NSCLC is broken down into three substages: 3A, 3B, and 3C. Each substage is defined by different combinations of values for T and N.

Stage 3A

There are four ways a cancer may qualify as stage 3A:

CriteriaTumor size (T)Spread to lymph nodes (N)
Criteria 1T1: The cancer is 3 centimeters (cm) across or smaller and hasn’t grown into the membrane around the lungs or into the bronchi.N2: Cancer has spread to lymph nodes below the area where the windpipe splits or into the space between the lungs. The cancer remains on the same side of the lung as the tumor.
Criteria 2T2: The cancer meets one or more of the following:
• grown larger than 3 cm but is smaller than 5 cm
• grown into the bronchi
• grown into the membranes surrounding the lungs
• is clogging the airways
N2: Cancer has spread to lymph nodes below the area where the windpipe splits or into the space between the lungs. The cancer remains on the same side of the lung as the tumor.
Criteria 3T3: The cancer meets one or more of the following:
• grown larger than 5 cm but is smaller than 7 cm
• grown into chest wall or its lining, nearby nerves, or the sac surrounding the heart
• there are two or more tumors on the same lobe of a lung
N1: The cancer has spread into lymph nodes in the lung or where the bronchus enters the lung. The cancer remains on the same side of the lung as the tumor(s).
Criteria 4T4: The cancer meets one or more of the following:
• grown larger than 7 cm
• grown into the space between the lungs or tissues, like the windpipe, diaphragm, esophagus, heart, or nearby large blood vessels
• there are two or more tumors in different lobes on the same side of the lung
N0 or N1: The cancer may or may not have spread to nearby lymph nodes on the same side of the lung as the tumor(s).

Stage 3B

There are four ways a cancer may qualify as stage 3B:

CriteriaTumor size (T)Spread to lymph nodes (N)
Criteria 1T1: The cancer is 3 cm across or smaller and hasn’t grown into the membrane around the lungs or into the bronchi.N3: Cancer has spread to the lymph nodes above the collarbone on either side of the body and/or has spread into nearby lymph nodes on the opposite side of the body from the tumor.
Criteria 2T2: The cancer meets one or more of the following:
• grown larger than 3 cm but is smaller than 5 cm
• grown into the bronchi
• grown into the membranes surrounding the lungs
• is clogging the airways
N3: Cancer has spread to the lymph nodes above the collarbone on either side of the body and/or has spread into nearby lymph nodes on the opposite side of the body from the tumor.
Criteria 3T3: The cancer meets one or more of the following:
• grown larger than 5 cm but is smaller than 7 cm
• grown into chest wall or its lining, nearby nerves, or the sac surrounding the heart
• there are two or more tumors on the same lobe of a lung
N2: Cancer has spread to lymph nodes below the area where the windpipe splits or into the space between the lungs. The cancer remains on the same side of the lung as the tumor(s).
Criteria 4T4: The cancer meets one or more of the following:
• grown larger than 7 cm
• grown into the space between the lungs or tissues, like the windpipe, diaphragm, esophagus, heart, or nearby large blood vessels
• there are two or more tumors in different lobes on the same side of the lung
N2: Cancer has spread to lymph nodes below the area where the windpipe splits or into the space between the lungs. The cancer remains on the same side of the lung as the tumor(s).

Stage 3C

There are two ways a cancer may qualify as stage 3C:

CriteriaTumor size (T)Spread to lymph nodes (N)
Criteria 1T3: The cancer meets one or more of the following:
• grown larger than 5 cm but is smaller than 7 cm
• grown into chest wall or its lining, nearby nerves, or the sac surrounding the heart
• there are two or more tumors on the same lobe of a lung
N3: Cancer has spread to the lymph nodes above the collarbone on either side of the body and/or has spread into nearby lymph nodes on the opposite side of the body from the tumor(s).
Criteria 2T4: The cancer meets one or more of the following:
• grown larger than 7 cm
• grown into the space between the lungs or tissues, like the windpipe, diaphragm, esophagus, heart, or nearby large blood vessels
• there are two or more tumors in different lobes on the same side of the lung
N3: Cancer has spread to the lymph nodes above the collarbone on either side of the body and/or has spread into nearby lymph nodes on the opposite side of the body from the tumor(s).

NSCLC happens when certain cell types in the lung begin to grow and divide out of control. This is due to DNA changes that promote excessive cell growth and division. These changes may be inherited or occur during your lifetime.

Smoking is a major risk factor for lung cancer. Smoking is estimated to be associated with about 90% of lung cancer diagnoses.

Other risk factors for NSCLC are:

After getting your medical history and doing a physical exam, a doctor may order the following tests to help diagnose and stage NSCLC:

The treatment of stage 3 NSCLC depends on many factors, such as:

  • size of the tumor(s)
  • location of the tumor(s)
  • which nearby lymph nodes or tissues the cancer has spread to
  • your age and overall health
  • your preferences

Sometimes, surgery can remove stage 3A NSCLC. If so, a doctor may recommend that you receive either chemoradiation or chemotherapy with immunotherapy before surgery to help shrink the tumor.

After surgery, you may receive adjuvant treatment to help kill the remaining cancer cells. Adjuvant treatment may be done with one or a combination of:

Some stage 3A NSCLCs cannot be removed with surgery. Additionally, stages 3B and 3C NSCLC are more widespread and typically cannot be removed with surgery. In this situation, your treatment may involve:

  • chemoradiation
  • radiation therapy or chemotherapy alone
  • immunotherapy

The outlook for people with stage 3 NSCLC depends on several factors. These can include:

  • size and location of the tumor(s)
  • which nearby lymph nodes or tissues the cancer has spread to
  • the specific type of NSCLC
  • the type of treatment used and how the cancer responds to it
  • your age and overall health

The 5-year survival rates for NSCLC diagnosed between 2012 and 2018 were:

  • Localized to lung: 65%
  • Spread to regional lymph nodes and tissues: 37%
  • Spread to distant tissues (metastatic cancer): 9%
  • Overall: 28%

Five-year survival rates estimate the percentage of people with a particular diagnosis who are alive 5 years after their diagnosis compared with people who do not have that diagnosis. Five-year survival rates don’t take into account advances in treatment or individual factors, like age or overall health.

One 2021 research paper notes that the median overall survival of people with stage 3 NSCLC ranges from 9–34 months, depending on the study that you look at.

A 2021 study found that people with stage 3A NSCLC who had surgery had a better outlook than those who didn’t have surgery.

People with stage 3B or 3C NSCLC who had chemoradiation had an improved outlook compared with those who had chemotherapy or radiation therapy alone.

What is the best treatment for stage 3 non-small cell lung cancer?

There’s no one “best” treatment for stage 3 NSCLC. Your doctor will take into account factors like the size and location of your cancer as well as your overall health to recommend a treatment that’s optimal for your individual situation.

Is stage 3 non-small cell lung cancer considered terminal?

Terminal cancer is cancer that cannot be managed or cured with treatment and will eventually lead to death. Many stage 3 NSCLCs are still treatable, although some are terminal.

Can stage 3 non-small cell lung cancer be cured?

Because it’s more advanced, it’s very challenging to remove stage 3 NSCLC completely. However, depending on the cancer’s characteristics and your age and overall health, some treatments do aim to cure the cancer versus relieve symptoms.

What’s the difference between stage 3 and stage 4 non-small cell lung cancer?

Stage 3 NSCLC has spread to nearby lymph nodes and tissues in the chest. Stage 4 NSCLC has spread to more distant organs and tissues, like the bones, liver, or adrenal glands.

Stage 3 NSCLC is when lung cancer has spread to nearby lymph nodes and tissues. There are three subtypes of stage 3 NSCLC, each with its own characteristics.

Sometimes surgery and adjuvant therapy can treat stage 3A NSCLC. Stages 3B and 3C are more widespread. Doctors typically treat them with one or a combination of chemotherapy, radiation therapy, or immunotherapy.

Most people with stage 3 NSCLC experience lung cancer symptoms. If you’re having concerning symptoms like persistent cough, shortness of breath, or unintended weight loss, make an appointment with a doctor to discuss them.