Lung cancer refers to a disease in which the growth of cells in the lung tissue gets out of control. This cell growth may cause metastasis, which is the invasion of adjacent tissues and penetration into the lungs unexpectedly. The vast majority of lung cancers are malignant epithelial cell tumors of the lung , caused by epithelial cell lesions. Lung cancer is the leading cause of cancer-related deaths in both men and women. Globally, 1.3 million people die from lung cancer each year. The most common symptoms include shortness of breath, cough (coughing up blood), and weight loss. Lung cancer is divided into small cell lung cancer and non-small cell lung cancer. This distinction is very important for the different treatment options available. Non-small cell lung cancer is treated with lung cancer surgery; while small cell lung cancer often responds better to chemotherapy and radiation therapy. The most common cause of lung cancer is long-term smoking. Non-smokers, who account for 15% of lung cancer patients, have the main causes of the disease, including genes, radon gas, asbestos, and air pollution (including secondhand smoke). Lung cancer can be seen on chest radiography (CR) and x-ray tomography (CT). Diagnosis is confirmed by biopsy, usually through fiberoptic bronchoscopy or CT. Treatment and prognosis options are based on the histological type of cancer, the stage of the cancer, and the patient’s condition. Possible treatment options are surgery, chemotherapy, and radiation therapy.