Epidemiology of lung cancer.

Lung cancer is the leading cause of cancer deaths for men and women in the United States, accounting for more cancer deaths since 1930 than all other cancer deaths combined. Whereas primary lung cancer was a relatively rare malignancy in the early 1900s, in 1994 there were approximately 170,000 new cases of lung cancer in the United States, of which roughly 100,000 were in men and 70,000 were in women. Despite numerous medical and surgical advances in the past several decades, there has not been a dramatic increase in the percentage of patients being cured of this lethal disease. Smoking is the primary factor responsible for the lung cancer epidemic, but there are numerous other environmental and genetic factors that have been implicated in the pathogenesis of the disease. Recently, it has become evident that passive smoking may also play a significant role in the development of lung cancer. Although screening has not been proven effective in the past, it may be time to reevaluate this technique because early detection of lung cancer affords the best chance for cure.