What is the prognosis for stage 4 lung cancer?

The American Cancer Society lists the 5-year survival rate for stage IV non-small-cell lung cancer as about one percent; stage IV small-cell lung cancer 5-year survival rates are at two percent. Mesothelioma has a 5-year survival rate of five to ten percent.

According to Lung Cancer International non-small-cell lung cancer represents 75 to 85 percent of all lung cancer cases, and two-thirds of these patients have such advanced stage cancer that it is considered inoperable.

Leaving metastatic, non-small-cell lung cancer untreated has a life expectancy of four to five months, according to Cancer.org. Treatment increases the life expectancy for non-small-cell lung cancer to between eight and 11 months.