Lung Cancer Staging

If the diagnosis is lung cancer, the doctor will want to learn the stage (or extent) of the disease. Lung cancer staging is done to find out whether the cancer has spread and, if so, to what parts of the body. Lung cancer often spreads to the brain or bones. Knowing the lung cancer stage of the disease helps the doctor plan treatment. Some tests used to determine the lung cancer stage and whether the cancer has spread include:

• CAT (CT) scan (computed tomography). A computer linked to an x-ray machine creates a series of detailed pictures of areas inside the body.
• MRI (magnetic resonance imaging). A powerful magnet linked to a computer makes detailed pictures of areas inside the body.
• Radionuclide scanning. Scanning can show whether cancer has spread to other organs, such as the liver. The patient swallows or receives an injection of a mildly radioactive substance. A machine (scanner) measures and records the level of radioactivity in certain organs to reveal abnormal areas.
• Bone Scan. A bone scan, one type of radionuclide scanning, can show whether cancer has spread to the bones. A small amount of radioactive substance is injected into a vein. It travels through the bloodstream and collects in areas of abnormal bone growth. An instrument called a scanner measures the radioactivity levels in these areas and records them on x-ray film.
• Mediastinoscopy/Mediastinotomy. A mediastinoscopy can help show whether the cancer has spread to the lymph nodes in the chest. Using a lighted viewing instrument, called a scope, the doctor examines the center of the chest (mediastinum) and nearby lymph nodes. In mediastinoscopy, the scope is inserted through a small incision in the neck; in mediastinotomy, the incision is made in the chest. In either procedure, the scope is also used to remove a tissue sample. The patient receives a general anesthetic.

Non-small cell lung cancer is staged according to tumor size, level of lymph node involvement and extent of distant metastases (spread). Stages are identified in the following ways:

• Stage 0 Lung Cancer. The cancer is limited to the lining of air passages and hasn't invaded lung tissue. The cancer can usually be eliminated when caught and treated.
• Stage I Lung Cancer. The cancer has spread to layers of lung tissue but has not reached the lymph nodes or beyond. There is a 60 percent to 80 percent chance of surviving the disease 5 years when it's caught and treated at this stage.
• Stage II Lung Cancer. The cancer has invaded neighboring lymph nodes or spread to the chest wall. There is a 40 percent to 50 percent chance of surviving the disease 5 years when it's caught and treated at this stage.
• Stage IIIA Lung Cancer. The cancer has spread from the lung to lymph nodes beyond the lung area. Cancer usually isn't treated surgically at this stage. There is a 15 percent to 30 percent chance of surviving 5 years when the disease is caught and treated with radiation or chemotherapy at this point.
• Stage IIIB Lung Cancer. The cancer has spread to areas such as the heart, blood vessels, trachea and esophagus - all within the chest. Cancer can't be treated surgically at this stage. A 10 percent to 15 percent chance of surviving 5 years exists when the disease is treated at this point.
• Stage IV Lung Cancer. In Stage 4 lung cancer the cancer has spread to other parts of the body, such as the liver, bones or brain. There is less than a 2 percent chance of surviving the disease 5 years when it's treated at this stage.