Lung cancer is divided into stages that are based on how much and how far the cancer has spread from the lungs throughout the rest of the body. Staging is critical in formulating a prognosis and developing an effective treatment plan.
- During stage IV lung cancer, the tumor may be any size and the cancer may have reached the lymph nodes. One or more tumors can be present in both lungs, cancer is found in the fluid that surrounds either the lungs or heart and the cancer has spread to other parts of the body not located near the lungs.
- The five-year survival rate once someone has reached stage IV is around one percent.