What Is the Survival Rate of Stage IV Lung Cancer?

The survival rate for patients diagnosed with stage 4 nonsmall-cell lung cancer is 1 percent, according to the American Cancer Society. The survival rate indicates the percentage of people with the disease who survive more than five years after diagnosis; many survivors live longer than five years past their diagnosis.

Ninety percent of the lung cancers diagnosed are nonsmall-cell lung cancers. Nonsmall-cell lung cancer spreads more slowly than small-cell lung cancer and therefore has a higher survival rate, as Healthline points out. A major factor affecting the survival rate is the stage at which the cancer is diagnosed. Those diagnosed with early stage 1 cancer have a five-year survival rate as high as 49 percent.

Survival rates are only general estimates that may or may not apply to any specific patient, as the American Cancer Society explains. Other factors that affect an individual patient's prognosis include his overall health, the types of treatment received and how the cancer responds to those treatments. In addition, genetic changes within the cancer cells themselves can affect the rate of the cancer's growth. Treatment may be less effective if the patient suffers from breathing difficulties or if symptoms are particularly severe, according to Healthline.