The lungs are a pair of spongy, air-filled organs that move oxygen through the body. The lungs are located within the rib cage and divided into sections or lobes. The right lung has three lobes and the left lung has two lobes. Lung cancer is a disease that attacks the lung tissue. It usually develops in adults older than age 65. It is the most common cancer worldwide, with 1.2 million new cases every year. Tobacco smoke is the leading cause of lung cancer. Smoking cigarettes, pipes, cigars or being exposed to secondhand smoke can increase the risk for this disease.
Of the two main types of lung cancer, non-small cell is the most common. Fortunately, it is also the slower growing of the cancers.
In its early stages, lung cancer may not cause any symptoms but may be found during a routine X-ray. If symptoms are present, they can include a chronic cough, trouble breathing, chest pain and unexplained weight loss.