INTRODUCTION: Lung cancer is a disease of uncontrolled cell growth in tissues of the lungs. It is one of the most common cancers in the United States, accounting for about 15 percent of all cases, or 170,000 new cases each year. It is also the worst cancer killer in America, taking more lives each year than breast, prostate and colorectal cancers combined, according to the American Cancer Society. It is the leading cause of cancer deaths in US women and is responsible for as many deaths as breast and all gynecological cancers combined.