Stage IV non-small cell lung cancer represents the most advanced form of the condition. The definitive feature of this stage is that cancer cells have spread out of the lungs to other parts of the body, according to Cancer Treatment Centers of America.
Tumors in stage IV non-small cell cancer can be any size, and cancer may or may not have spread to nearby lymph nodes. This stage has two variants: M1A or M1B, explains Cancer Treatment Centers of America. M1A means the cancer has spread to the other lung and cancer cells are present in the fluid surrounding the lung and the heart. M1B means the cancer has metastasized to lymph nodes located in other parts of the body or to other body organs including the brain, kidney, liver and bones.
At this stage, cancer cells are often present in various parts of the body, making treatment a challenge, the American Cancer Society reports. The treatment option chosen depends on how far the cancer has spread, where it has spread, the number of tumors present in each location, and the patient’s overall health. Surgery to drain accumulated fluid around the lungs helps relieve symptoms. Physicians recommend chemotherapy for cancer that has spread throughout the body.