Definition of Lung cancer

Lung cancer: Cancer of the major organ of respiration - the lung. Lung cancer is one of the most common forms of cancer. Since the majority of lung cancer is diagnosed at a relatively late stage, only 10% of all lung cancer patients are ultimately cured. Eight out of 10 lung cancers are due to tobacco smoke. Most lung cancers are classified as either small cell or non-small cell cancers. Persistent cough and bloody sputum can be symptoms of lung cancer. Lung cancer can be diagnosed based on examination of sputum, or tissue examination with biopsy using bronchoscopy, needle through the chest wall, or surgical excision.