The stage of lung cancer determines the treatment options in a given case and directly influences survival. Localized: About 16% of cases are localized (i.e. confined to the primary site) and show 5-yr relative survival rate of 55.2%. Regional: About 22% of cases have spread to regional lymph nodes at the time of diagnosis. The 5-yr survival rate is 28%. Distant: Almost 57% of cases have metastasized to distant sites and show a 5-yr survival rate of only 4.3%. Unknown: About 5% of cases remain unstaged and have a 5-yr survival rate of 7.4%. Source : National Cancer Institute website.