Non-Small Cell Lung Cancer Stage III

Stage 3 non-small cell lung cancer represents a complex form of lung disease where cancer has spread beyond the lungs to nearby tissues and lymph nodes, but not to distant organs. About 30% of people with non-small cell lung cancer are diagnosed at this stage, facing a challenging but potentially treatable condition.

Table of contents

• What is Stage 3 Non-Small Cell Lung Cancer?
• Understanding the Substages: 3A, 3B, and 3C
• Where the Cancer Can Spread
• How Stage 3 NSCLC is Diagnosed
• Treatment Options

What is Stage 3 Non-Small Cell Lung Cancer?

Stage 3 non-small cell lung cancer is sometimes called locally advanced cancer.^[1] This means the cancer has grown beyond where it started in the lung and has spread to nearby areas, but it has not yet reached distant parts of the body.^[2]

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, making up about 80% to 85% of all lung cancer cases.^[6] When doctors say you have stage 3 NSCLC, it means your cancer has not spread beyond the lungs and the nearby lymph nodes.^[2]

Roughly 20% to 35% of people with NSCLC are diagnosed at stage 3.^[3][6] This stage represents a point between localized disease and cancer that has spread to distant organs. The complexity of stage 3 disease means that patients form a highly diverse group, with tumors that can differ in size, location, and how far they have spread from where the cancer started.^[6]

Understanding the Substages: 3A, 3B, and 3C

Stage 3 non-small cell lung cancer is divided into three separate substages called 3A, 3B, and 3C. The differences between each substage are based on the size of the tumor, where it is located, and whether it has spread to the lymph nodes or not.^[2]

Stage 3A

Stage 3A has four possible scenarios. In general, the cancer may have grown or spread to the lymph nodes on the same side of the chest where it started.^[2]

The cancer can be 3 centimeters or smaller and may have spread to lymph nodes in the area where the windpipe divides or in the space between the lungs on the same side as the cancer.^[1] It may be between 3 and 5 centimeters and could have grown into the main airway of the lung, the membrane covering the lung, or caused the lung to partly or completely collapse.^[1]

Stage 3A can also mean the cancer is between 5 and 7 centimeters and has grown into the chest wall, ribs, muscle, skin, or nerves close to the lung, with two or more areas of cancer in the same lobe of the lung.^[1] In some cases, the cancer is larger than 7 centimeters and has grown into the diaphragm (the muscle below the lung that helps with breathing), the center area of the chest, the heart, major blood vessels, the windpipe, or the food pipe.^[1]

Stage 3B

In stage 3B, the cancer may have grown and spread to the lymph nodes on either side of the chest, neck, or above the collarbone.^[2] The tumors can range from 3 centimeters or smaller to larger sizes.^[1]

Stage 3B can mean the cancer has spread to lymph nodes in the space between the lungs on the opposite side of the lung with cancer, or to lymph nodes where the bronchus (main airway) enters the lung in the opposite lung, or to lymph nodes in the side of the neck or above the collarbone on either side of the body.^[1]

Stage 3C

Stage 3C is the most advanced stage within stage 3. The cancer may have grown even larger and spread to the lymph nodes on the other side of the chest from where it started, either side of the neck, or above the collarbone.^[2]

Where the Cancer Can Spread

In stage 3 lung cancer, the cancer may have grown or spread to one or more of the following areas:^[2]

• Lungs
• Nerves
• Blood vessels
• Chest wall
• Other organs located in the chest
• Diaphragm (muscle that helps with breathing)
• Heart and heart lining
• Lymph nodes in either side of the chest
• Mediastinum (space between lungs)
• Pleura (lung lining)
• Bronchus (main airway of lungs)
• Esophagus (food pipe)
• Spine

How Stage 3 NSCLC is Diagnosed

Doctors use a system called TNM staging to understand the extent of the cancer. TNM stands for Tumor size, lymph Node spread, and Metastasis (spread to distant organs).^[6]

For stage 3 NSCLC, the cancer can be classified as T1 through T4 for tumor size, N0 through N3 for lymph node spread, and all stage 3 cancers are M0, meaning there is no spread to distant organs.^[6]

When you have symptoms of lung cancer, your doctor will likely order a chest X-ray as the first imaging test. If it suggests you have cancer, you’ll have follow-up tests such as a CT scan (a detailed imaging test that uses X-rays and computers to create pictures of the inside of your body).^[6]

After non-small cell lung cancer has been diagnosed, tests are done to find out if cancer cells have spread within the chest or to other parts of the body. The stage of the cancer helps your doctor decide which treatment you need and can also give some idea of your outlook.^[1]

Treatment Options

Stage 3 non-small cell lung cancer presents a major challenge for treatment. The management of this stage requires discussion in teams of different medical specialists, as treatment often involves a combination of different approaches.^[3]

What Does Unresectable Mean?

The majority of cancer found in people with stage 3 NSCLC is unresectable. This means the cancer cannot be removed with surgery.^[2] Most patients are diagnosed with a disease that cannot be surgically removed, and around 40% of patients with inoperable stage 3 treated only with chest radiation therapy experienced very limited survival.^[7]

Chemoradiation

Chemoradiation is when chemotherapy and radiation therapy are given together. This combination may be offered before surgery for stage 3 non-small cell lung cancer if you are well enough to have this treatment.^[8]

Chemoradiation may also be given if you won’t be having surgery and are well enough to tolerate this treatment. The chemotherapy drugs most often used with chemoradiation include cisplatin with etoposide.^[8] Patients who receive chemotherapy and radiation therapy together can achieve a 3-year survival of approximately 27%.^[7]

Surgery

Surgery may be offered after chemoradiation if the treatment shrinks the tumor enough to make removing it possible.^[8] Different types of surgery may be performed depending on the location and extent of the cancer.

A lobectomy removes the lobe of the lung where the tumor is located. A pneumonectomy removes the whole lung. Other surgical procedures may remove parts of the airway tubes, muscles, nerves, blood vessels, and other tissues near the lung.^[8]

For stage 3A non-small cell lung cancer, you may be offered surgery after chemoradiation if the cancer has responded to treatment and you are healthy enough for the procedure. For stage 3B and 3C, surgery is usually not offered because it will not help given where the cancer has spread.^[8]

Chemotherapy

Chemotherapy uses drugs to kill cancer cells or stop them from growing. The chemotherapy drug combinations that may be used include cisplatin with vinorelbine or etoposide, cisplatin or carboplatin with gemcitabine, cisplatin or carboplatin with docetaxel, and several other combinations.^[8]

For stage 3A, you may have chemotherapy before surgery if you cannot be given radiation therapy. Chemotherapy may also be given after surgery if none was given before or if the cancer responded to chemotherapy given before surgery. For stage 3B and 3C, you may have chemotherapy by itself if you are not well enough to have chemoradiation or radiation therapy.^[8]

Targeted Therapy

Targeted therapy may be used to treat stage 3 non-small cell lung cancer. The type of targeted therapy you have will depend on the type of genetic change found during diagnosis and whether there is a treatment available for that specific change.^[8]

EGFR targeted therapy works on cancers that have changes in the EGFR gene. EGFR is a receptor on the surface of cells that sends signals allowing them to grow and divide. A change in this gene can cause cancer cells to grow and divide more than they should.^[8]