Lung cancer is a disease in which abnormal or cancerous cells grow in the lungs.
The abnormal cells no longer do the work of normal cells. Instead the cancer cells replace and destroy healthy tissue in the lungs. About one in ten heavy smokers will get lung cancer. Doctors estimate that the smoker's high risk for lung cancer is lowered to almost normal just after 10 years after he or she stops. This year, more Canadian women will die form lung cancer than from breast cancer.