Staging for lung cancer within each stage is highly complex and detailed, with many subgroups. Clinicians initially split it up into classifications of small cells and non-small cells. Doctors usually use the tumor size and spread to guide non-small cell lung cancer in the following way:
What is occult or hidden stage of lung cancer?
Cancer does not appear on imaging scans but cancer cells may appear in the phlegm or mucus and may have entered other body parts.
What is stage 0 lung cancer?
The abnormal cells are found only in the top layers of cells lining the airways.
What is stage I lung cancer?
A tumor under 5cms has developed in the lungs and is not spread to other parts of the body.
What is stage II lung cancer?
The tumor is smaller than 5 cm and may have spread to the lymph nodes in the lung area. These can also be smaller than 7 cm and spread to surrounding tissues but not to lymph nodes.
What is stage III lung cancer?
Cancer has reached to other parts of the lung along with surrounding area and also has spread to the lymph nodes.
What is stage IV lung cancer?
Cancer has spread to other body parts such as bones or brain.