What causes lung cancer, and who gets it?
The major cause of lung cancer is smoking. The average patient is a man or a woman between 50 and 70 years who has smoked for many years. In patients who never smoked, 30% of lung cancers are caused by passive smoke or from smoke inhaled from other people’s cigarettes (secondhand smoke). If a person stops smoking, the risk of cancer decreases steadily each year as normal cells replace abnormal cells. Other causes of lung cancer are chemicals, such as asbestos, radon, uranium, arsenic and certain petroleum products. Exposure to these chemicals in combination with cigarette smoking sharply increases the risks of developing cancer. Heredity or family history is also linked with development of lung cancer. Studies have shown that blood relatives of lung cancer patients have increased risk of developing the disease.
