The stage of a tumor refers to the extent to which lung cancer has spread in the body. Staging involves both evaluation of a tumor's size, as well as the presence or absence of metastases in the lymph nodes or in other organs. Staging is important for determining how a particular tumor should be treated. Staging of a tumor is also critical in estimating the prognosis of a given patient, with higher-stage tumors having a worse prognosis than lower-stage tumors.
Doctors use several tests to accurately stage lung cancer, including blood tests, X-rays, CT scans, bone scans, and PET scans. An abnormal blood chemistry test may signal the presence of metastases in the bone or liver. Radiological procedures document the size of a tumor, as well as its spread to other organs.
As far as treatment goes, if the lung cancer can be successfully removed with surgery, the patient has an excellent chance of surviving at least one year, and usually a better than 50% chance of living for five years or more after that. The challenge is detecting lung cancer early enough to make surgery possible.