Lung Cancer Stages

Staging is the process of finding out how far lung cancer has spread within the lungs or to other parts of the body. This is very important because your treatment and prognosis (the outlook for your recovery) depend in large part on the stage of your cancer.

Accurate staging is probably the most important part of lung cancer treatment because it allows doctors to choose the most appropriate therapy (and can help you avoid ineffective therapy). During staging, it is important to verify any X-ray findings that suggest more advanced cancer because these X-rays can sometimes be misleading. Your cancer could be less advanced and your treatment options could be different than X-rays suggest. 

Determining the Stage

At Seattle Cancer Care Alliance, the lung cancer team has a methodical and scientific approach to lung cancer staging that allows many patients to have more aggressive therapy with a goal of curing their disease, even when this may not have seemed possible based on initial X-ray evaluations.

Several methods may be used to determine the stage of the disease, including the following:

  • Computed tomography (CT) scan—An X-ray machine linked to a computer creates a series of detailed pictures of areas inside the body.
  • Magnetic resonance imaging (MRI) scan—A magnet connected to a computer uses radiofrequency waves to make detailed pictures of areas inside the body.
  • Positron emission tomography (PET) scan—A scanner checks the body after an injection of a small amount of radioactive material that may collect in cancer cells.
  • Mediastinoscopy—A lighted scope is inserted through an incision in the neck to look at organs, tissues, and lymph nodes in the chest.
  • Bone scan—A scanner checks bones after an injection of a small amount of radioactive material that may collect in rapidly dividing cells, such as cancer cells.

Your doctor may also want to do a brain scan or biopsies of lymph nodes or suspicious areas seen on X-rays.

Non-small Cell Lung Cancer Stages

Non-small cell lung cancer is assigned an overall stage of I, II, III, or IV. The stages may be further subdivided into A and B, based on more precise features of the cancer.

  • Stage I: The cancer is limited to the lung and has not spread to the lymph nodes; the tumor is generally smaller than 2 inches (5 centimeters) across.
  • Stage II: The cancer has spread to some lymph nodes near the original tumor; the tumor may be larger than 2 inches, or it may be a smaller tumor that involves the chest wall, diaphragm, pleura, or lymph nodes in the lung.
  • Stage III: The cancer is difficult to remove and may not be removable at all; the cancer has spread to nearby tissue or distant lymph nodes.
  • Stage IV: There are one or more tumors in both lungs, cancer may be found in fluid around the lungs or the heart, and cancer may have spread to other parts of the body, including the brain, liver, kidneys, or bone.

Small Cell Lung Cancer Stages

Small cell lung cancer is staged as limited or extensive.

  • Limited stage: The cancer is located on one side of the chest and involves one region of the lung, the mediastinum (area between the lungs), and lymph nodes. One-third of small cell lung cancer patients have limited stage.
  • Extensive stage: The cancer has spread outside the lungs to other parts of the body.

Metastatic, Advanced, or Recurrent Lung Cancer 

Lung cancer that has already spread to another part of the body, such as the liver, bones, brain, or distant lymph nodes, at the time of diagnosis is called metastatic lung cancer or advanced lung cancer.

If lung cancer comes back after treatment, it’s called recurrent. If cancer reappears in the lung, it is a local recurrence. Lung cancer that recurs in another part of the body is metastatic or advanced.