Stage 3 lung cancer is diagnosed when a tumor has spread into the main airways (bronchi) and nearby lymph nodes. The cancer has not yet spread to other parts of the body, in a process known as metastasis.

What Is Stage 3 Lung Cancer?

There are two types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

The staging is different for each type due to the differences in the diseases. Doctors will use staging information collected from tests to create treatment plans and predict outcomes.

NSCLC staging uses a scale numbered stage 0 through stage 4. Stages are also sometimes written using Roman numerals — stage 3 is also referred to as stage III. Doctors can also stage cancers as being limited (in the same organ), regional (spread into the lymph nodes), or distant (found in other organs).

The American Joint Committee on Cancer designed a staging system known as the TNM scale. Staging is based on the answers to three main questions:

• T (tumor size) — How large is the main tumor, and how much has it spread?
• N (nodes) — Has the cancer spread into the lymph nodes?
• M (metastases) — Has the cancer metastasized (spread) to distant organs in the body?

SCLC is rarely staged using the TNM system. Instead, doctors will classify cases as “limited stage” or “extensive stage,” depending on where the tumor is located and how far it has spread.

Non-Small Cell Lung Cancer

Stage 3 NSCLC can be broken into three different stages: 3A, 3B, and 3C. For each of these stages, there are many different variables. Your health care provider can help you understand the staging of your particular diagnosis.

Characteristics of stage 3A lung cancer can include the following:

• The tumor may be less than 3 centimeters across — or it can be larger than 7 centimeters across.
• The tumor has spread into the nearby lymph nodes, the bronchi, the membranes surrounding the lungs (visceral pleura), and/or other nearby structures.
• There may be two or more separate tumor nodules in different lobes of the same lung.
• The cancer has not metastasized.

Characteristics of stage 3B lung cancer can include the following:

• The tumor may be less than 3 centimeters across — or it may be larger than 7 centimeters across.
• The tumor has spread to the lymph nodes near the collarbone, the main airways, the space between the lungs (mediastinum), the windpipe (trachea), esophagus, backbone, and/or other nearby structures.
• There may be two or more separate tumors found in the same lung lobe.
• The cancer has not metastasized.

Characteristics of stage 3B lung cancer can include the following:

• The tumor is 5 centimeters or larger across.
• The tumor has spread into the chest wall, the sac surrounding the heart, the mediastinum, trachea, backbone, and/or other nearby structures.
• There are two or more separate tumors found in the same lung lobe.
• The cancer has not metastasized.

Small Cell Lung Cancer

The two stages of SCLC are limited stage and extensive stage.

Limited-stage SCLC is diagnosed when the cancer is found in only one lung, and the cancer may have spread to the lymph nodes. These can include nodes found above the collarbone and those in the center of the chest.

Extensive-stage SCLC is diagnosed when the cancer may have spread through both lungs, the lymph nodes, or other areas of the body. Cancer that has spread to the visceral pleura is also considered to be extensive stage. Roughly 2 of every 3 people are diagnosed with extensive disease when their cancer is discovered.

Symptoms of Stage 3 Lung Cancer

You can experience lung cancer symptoms at any stage, but they are more common in the later stages after the disease has progressed. Common lung cancer symptoms at any stage can include:

• Shortness of breath
• Coughing
• Tiredness
• Chest pain
• Weight loss

Stage 3 lung cancer may also cause additional signs and symptoms, which may vary depending on the size of the tumor and where it has spread. They can include:

• Swollen lymph nodes, which can appear as lumps
• Bone or joint pain
• Hoarseness

Treatments for Stage 3 Lung Cancer

Treatment plans for stage 3 lung cancer typically use a combination of therapies and require input from a team of doctors. This team may include a medical oncologist, a thoracic surgeon, and a radiation oncologist. The team will take into account the size and spread of your tumor, what lymph nodes are being affected, and your overall health.

A cancer diagnosis is stressful, and deciding on a treatment plan can add to this stress. Ask your doctor to explain the treatments, risks, and benefits for all potential treatment options. You may also want to seek a second opinion from another doctor to help you make your decision.

Treating Stage 3 NSCLC

Treatment recommendations for stage 3 NSCLC can be divided by stage.

Stage 3A

First-line treatments for stage 3A NSCLC include surgery or a combination of chemotherapy and radiation (known as chemoradiation). If you have surgery and your tumor has a mutation in the EGFR gene, you may also be treated with the targeted therapy drug osimertinib (sold as Tagrisso).

If you cannot tolerate surgery or chemoradiation, your doctor may recommend immunotherapy treatment. First-line treatments include pembrolizumab (Keytruda) or cemiplimab (Libtayo).

Stage 3B or 3C

Stage 3B and 3C NSCLC cannot be easily treated using surgery because the cancer has spread into the lymph nodes and nearby structures in the lungs. Your cancer team will most likely recommend chemoradiation for stage 3B or 3C NSCLC. If this approach controls your cancer, you may also begin treatment with the immunotherapy drug durvalumab (Imfinzi) to keep progress stable.

In some cases, stage 3B or 3C lung cancer can be difficult to treat. Your cancer team may recommend a clinical trial with a newer treatment as an option.

Treating SCLC

SCLC may be classified as limited or extensive stage. Your cancer team will discuss with you which options are best to treat your specific case.

Limited-Stage SCLC

In most cases, surgery is not an option to treat limited-stage SCLC because the tumor has spread to nearby structures, is too large, or cannot be easily reached. Instead, standard treatment uses concurrent chemoradiation (chemotherapy and radiation given at the same time). However, this combination can result in more side effects than if chemotherapy or radiation were given alone. People who cannot tolerate the combination may be given chemotherapy alone, followed later by radiation.

In roughly 50 percent of SCLC cases, the cancer will spread to the brain. You may be given radiation treatment to the brain to help prevent the spread.

Extensive-Stage SCLC

People with extensive-stage SCLC are generally not candidates for surgery or radiation therapy because the cancer has progressed too far for these treatments to be effective. Instead, whole-body (systemic) treatments are used to treat cancer that has spread to several places around the body. Chemotherapy using etoposide combined with platinum-based drugs is a common combination used to treat extensive SCLC.

Immunotherapy drugs, such as Imfinzi and atezolizumab (Tecentriq) can also be used in combination with etoposide and platinum-based chemotherapy drugs as first-line treatments. These drugs may significantly shrink tumors. However, in nearly all cases, cancer will relapse (return).

If the cancer has spread into the airways or is causing bleeding or shortness of breath, radiation or laser surgery can help alleviate these symptoms. In cases where the cancer has spread into the backbone, radiation may also be used to relieve pain.

Stage 3 Lung Cancer Outlook

Survival rates are used to give you a general idea of how many people with the same kind and stage of cancer live for a certain amount of time. Studies will typically look at the five-year survival rate for different types of cancer. These rates are only estimates and cannot predict what will happen to a particular person.

People with NSCLC that has spread regionally have a five-year survival rate of 37 percent. For SCLC, the five-year survival rate is 18 percent. It is important to note that these numbers do not take into account different subtypes of cancer, age, overall health, and any genetic mutation in your cancer cells.

Lung cancer treatments continue to improve over time, and the outlook for people with lung cancer has also improved.

Talk With Others Who Understand

MyLungCancerTeam is the social network for people with lung cancer and their loved ones. On MyLungCancer, more than 6,000 members come together to ask questions, give advice, and share their stories with others who understand life with lung cancer.

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