Abstract
Lung cancer is currently the leading cause of cancer death in the United States and also the most common tumor worldwide. Changes in the distribution of histologic types over the past two decades in the United States, as well as high rates of lung cancer in certain subpopulations, require explanation. While cigarette smoking and specific occupational exposures are firmly established as important risk factors for lung cancer, recent work provides evidence that other factors may play a role either as independent risk factors or as modifiers of the effect of smoking. This paper reviews the epidemiology of lung cancer, with an emphasis on developments in the past decade.