Early lung cancer as a potential target for chemoprevention

Carcinoma of the lung is the most common cause of death from cancer in the United States. In considering lung cancer for possible chemoprevention trials, we have analyzed the data collected by the collaborative NCI program on early lung cancer. The data indicate that at least 12 years of study of 80,000 people at risk for lung cancer (adult male cigarette smokers) would be required to establish a 25% reduction in squamous carcinoma of the lung. No intermediate markers of developing lung cancer are presently available to shorten the observation period. It is concluded that a study of the magnitude required is not feasible at the present time.