Lung cancer etiology: challenges of the future.

The 1982 Report of the Surgeon General of the U.S. Public Health Service concluded that "cigarette smoking is the major single cause of cancer mortality in the United States" and that "85 percent of lung cancer cases are due to smoking". Thus, major emphasis should be placed on school health education programs designed to prevent young people from smoking. Those students who are already cigarette smokers should be provided with an opportunity to attend smoking cessation courses with the hope that they stop. However, as long as society condones tobacco usage, millions of people will smoke, and millions of others will be involuntarily exposed to tobacco smoke. In this communication we have discussed the need for future research on the etiology of lung cancer. This includes the observation of a shift toward an increasing proportion of adenocarcinoma compared to squamous cell carcinoma of the lung in men, more detailed knowledge of the effects of macro- and micronutrients in the etiology of lung cancer, a clear delineation of the impact of tumor initiators, tumor promoters, and cocarcinogens in the development of lung cancer in cigarette smokers, and a study of the effects of the low-yield cigarette on the lung cancer risk of smokers. Finally, we reviewed the present knowledge as to the possible association of passive smoke exposure and lung cancer. Here we have placed major emphasis on the need for a close cooperation between epidemiologists and clinical biochemists in risk assessment.