The American Cancer Society estimates that 177, 000 new cases of lung cancer are diagnosed annually in the United States of America. The estimation in sex is 112, 200 men and in women the estimation is 81, 700, with a 5-year mortality rate of approximately 85%, more than 164, 000 of these individuals will eventually die from the disease. More than 540, 000 will die this year of cancer (nearly 1, 500) per day. The 1 - year relative survival rate for lung cancer has risen from 32% in 1973 to 41% in the 1990's.

However the combined 5 - year relative survival rate for all lung cancer stages remains between 13 - 15%. Although the 5 - year survival rate is 47% for cases detected when the disease is at an early, localized stage, only approximately 15% of malignant lesions are identified at this early stage of the disease manifestation process. According to 1996 projection, the leading three causes of cancer deaths in men and women will be as follows: This high percent of deaths in lung cancer is mainly made of men and women smokers of America, and the remainder of people are exposed to secondhand smoke. The great majority of lung cancer cases could be prevented and thousands of lives could be saved each year if people just quit smoking. Although cigarette smoking is the major determinant of lung cancer risks, exposure to radon decay products, asbestos, or ionizing radiation (X or gamma rays) can also increase lung cancer risk. The combination of cigarette smoking and asbestos exposure increases the risk of lung cancer 50 - fold.

Epidemiological studies have shown an increased risk of lung cancer in non-smokers chronically exposed to tobacco smoke. Non-smokers married to smokers have a 30% higher risk of lung cancer than non-smokers married to non-sm.