Lung cancer kills more than 1.4 million people worldwide each year. Lung cancer is the leading cause of cancer deaths in the industrialized world, exceeding the number of deaths from breast, colon, ovarian, and prostate cancers combined. In the United States, there were more than 200,000 new cases of lung and bronchial cancer cases in 2007. The five year survival rate of lung cancer patients is roughly 15% and has been unchanged for decades. Early diagnosis of lung cancer has been identified as a key strategy for improving prospects for survival, yet 65-80% of patients who have the disease present with late stage disease. Current and former smokers comprise 85-90% of lung cancer cases.
