Following the diagnosis of lung cancer, your doctor will wish to determine the stage of your lung cancer. This is a method of assessing to what extent your lungs have been affected by the tumour. Once the doctor has confirmed the stage of your cancer, a treatment plan can be discussed with you.

The following stages are used for non-small cell lung cancer:

• Occult (hidden) : cancer cells are found in the sputum but no tumour can be found in the lung by imaging or bronchoscopy, or the primary tumour is too small to be assessed.
  
  
• Stage 0 : cancer is limited to the lung and is found in a few layers of cells only.
  
  
• Stage I : cancer is found in the lung only.
  
  
• Stage II : cancer has spread to nearby lymph nodes or to nearby tissues.
  
  
• Stage III : cancer has either spread to the lymph nodes in the tracheal wall, including the chest wall and diaphragm (stage IIIA) or to the lymph nodes on the opposite side of the chest or in the lower neck (stage IIIB).
  
  
• Stage IV : cancer has spread to other parts of the body.
  
  
• Recurrent non-small cell lung cancer is cancer that has come back after it has been treated.