Lung cancer is the leading cause of cancer-related death in the United States. An estimated 219,440 new cases (116,090 men; 103,350 women) of lung and bronchus cancer were diagnosed in 2009, and 159,390 deaths (88,900 men; 70,490 women) occurred from the disease. 1 Only 15% of all lung cancer patients are alive 5 years or more after diagnosis (http://seer. cancer. gov/statfacts/html/lungb. html). Common symptoms of lung cancer include cough, dyspnea, weight loss, and chest pain; symptomatic patients are more likely to have chronic obstructive pulmonary disease.

The primary risk factor for lung cancer is smoking, which accounts for more than 85% of all lung cancer-related deaths. 2 The risk for lung cancer increases with the number of cigarettes smoked per day and the number of years spent smoking. In addition to the hazard of first-hand smoke, exposed nonsmokers have an increased relative risk for developing lung cancer. 3 Radon gas, a radioactive gas that is produced by the decay of radium 226, is the second leading cause of lung cancer. 4 The decay of this isotope leads to the production of substances that emit alpha-particles, which may cause cell damage and therefore increase the potential for malignant transformation. Data suggest that postmenopausal women who smoke or are former smokers should not undergo hormone replacement therapy, because it increases the risk for death from non–small cell lung cancer (NSCLC). 5