The Epidemiology of Lung Cancer

¹ The Pulmonary and Critical Care Division, Department of Medicine, and the New Mexico Tumor Registry, University of New Mexico School of Medicine, Albuquerque.

A worldwide lung cancer epidemic has occurred during the 20th century. Although the incidence of lung cancer is presently declining among middle-aged men in some countries, it is increasing among women in many developed countries. The rise of smoking in developing nations will inevitably be followed by spread of the lung cancer epidemic. Epidemiologic research has convincingly established that cigarette smoking is a cause of lung cancer, accounting for the majority of lung cancer cases in most regions. Other remediable causes, including exposure to occupational agents and indoor air pollutants, have been identified. This evidence has provided a strong impetus for the implementation of a broad range of strategies to reduce the occurrence of lung cancer. Smoking prevention and cessation programs have been implemented by governmental and nongovernmental organizations, and workplace exposures to atmospheric carcinogens have been reduced through regulatory and other actions. It is encouraging that lung cancer mortality is beginning to decline among middle-aged men in the United States, and further reductions are projected for both men and women. On the other hand, smoking remains prevalent throughout the world, and the association of smoking with lung cancer has not stopped nonsmoking youths from becoming smokers.