肺癌
Lung cancer is responsible for 1.3 million deaths worldwide annually, and is the most common cause of cancer-related death in men and the second most common in women. The most common cause of lung cancer is long-term exposure to tobacco smoke. Lung cancer in non-smokers, who account for approximately 15% of cases, is often attributed to a combination of genetic factors, radon gas, asbestos, and air pollution.