Lung cancer is a type of cancer that begins in the lungs. Your lungs are two spongy organs in your chest that take in oxygen when you inhale and release carbon dioxide when you exhale.
Lung cancer is the leading cause of cancer deaths in the world among both men and women. Lung cancer claims more lives each year than do colon, prostate, ovarian and breast cancers combined.
Lung cancer typically doesn’t cause signs and symptoms in its earliest stages. Signs and symptoms of lung cancer typically occur only when the disease is advanced.