Epidemiology of Lung Cancer

Many causes of lung cancer have been identifi ed, including active cigarette smoking 3 ; exposure to secondhand cigarette smoke (passive smoking) 4 ; pipe and cigar smoking 5 ; occupational exposure to agents such as asbestos, nickel, chromium, and arsenic 6 ; exposure to radiation, including radon gas in homes and mines 7 ; and exposure to indoor and outdoor air pollution. 8 Despite the identifi cation of this constellation of wellestablished causal risk factors, the global epidemic of lung cancer is primarily caused by a single factor: cigarette smoking. This dominance of cigarette smoking refl ects effective marketing and promotion of an addicting and deadly product by multinational corporations. 9 Background: Ever since a lung cancer epidemic emerged in the mid-1900s, the epidemiology of lung cancer has been intensively investigated to characterize its causes and patterns of occurrence. This report summarizes the key fi ndings of this research. Methods: A detailed literature search provided the basis for a narrative review, identifying and summarizing key reports on population patterns and factors that affect lung cancer risk. Results: Established environmental risk factors for lung cancer include smoking cigarettes and other tobacco products and exposure to secondhand tobacco smoke, occupational lung carcinogens, radiation, and indoor and outdoor air pollution. Cigarette smoking is the predominant cause of lung cancer and the leading worldwide cause of cancer death. Smoking prevalence in developing nations has increased, starting new lung cancer epidemics in these nations. A positive family history and acquired lung disease are examples of host factors that are clinically useful risk indicators. Risk prediction models based on lung cancer risk factors have been developed, but further refi nement is needed to provide clinically useful risk stratifi cation. Promising biomarkers of lung cancer risk and early detection have been identifi ed, but none are ready for broad clinical application. Conclusions: Almost all lung cancer deaths are caused by cigarette smoking, underscoring the need for ongoing efforts at tobacco control throughout the world. Further research is needed into the reasons underlying lung cancer disparities, the causes of lung cancer in never smokers, the potential role of HIV in lung carcinogenesis, and the development of biomarkers. CHEST 2013; 143(5)(Suppl):e1S–e29S