Once a patient has been diagnosed with lung cancer, doctors will provide information about the patient's current cancer stage. Understanding the stage of lung cancer can also help people understand the progression of the disease and which parts of the lungs are affected.

Stage 3 lung cancer has spread to nearby tissues or distant lymph nodes in the body. In general, lung cancer at this stage is curable, but prognosis and survival depend on many factors, including age, treatments, and overall health.