Staging is done to identify the extent of lung cancer at diagnosis. The stage of lung cancer will dictate its treatment and prognosis.

Non-small cell lung cancer (NSCLC)

Stage I
Cancer not more than 5 cm in size and has not invaded beyond the underlying  lung tissue and hasn't spread to the lymph nodes. 

Stage II
Cancer more than 7 cm in size or between 5-7 cm in size but has spread to  neighbouring lymph nodes or invaded the adjacent pleura, diaphragm or nerve.

Stage IIIA
Cancer that has spread from the lung to lymph nodes in the centre of the chest. 

Stage IIIB
Cancer that has spread locally to vital structures such as the heart, blood  vessels, trachea and esophagus and/or spread to multiple lymph nodes on  both sides of the chest.

Stage IV
The cancer has spread to another lung lobe or other parts of the body, such as  the liver, bones or brain or there is presence of malignant pleural effusion  (collection of fluid surrounding the lungs).
 

Small cell lung cancer (SCLC)

Limited 
The cancer in the lung including lymph nodes are confined to only 1 side of  the chest

Extensive 
There is evidence of cancer spread to the other lung and/or lymph nodes  and/or other organs.
 

Updated:: 14/03/2019 []