Abstract

Pulmonary carcinoma is the most commonly diagnosed cancer in worldwide, and it is the most common cause of cancer death. A variety of factors, such as ethnicity, age, gender, geographic location, and socioeconomic status, influence the rate in spesific groups. The known behavioral and environmental causes--cigarette smoking, diet, asbestos and other occupational carcinogens, radon, and environmental tobacco smoke--are responsible for the majority of cases. Passive smoking, the involuntary inhalation of tobacco smoke by nonsmokers, has also been found to cause lung cancer. Moreover familial aggregation and increased familial risk for lung cancer have been reported.