Epidemiology, prevention, prognostic factors, and natural history of lung cancer.

In the year under review, studies showed the effects of smoking on the occurrence of lung cancer outside North America; currently, China is a country of considerable interest. A number of studies were also reported on occupational factors in lung cancer etiology, with risks confirmed in the steel industry. Increasing interest, mostly generated by the tobacco industry, relates to passive smoking and lung cancer. Attempts continue to refine prognostic factors, especially in small cell lung cancer.