Also known as:
Lung cancer starts when abnormal cells grow out of control in the lung. These cells can invade nearby tissue and form tumors. Lung cancer can start anywhere in the lungs and affect any part of the respiratory system.
The cancer cells can spread, or metastasize, to lymph nodes and other body parts.
Lung cancer, the leading cause of cancer death worldwide, is classified as non-small cell lung cancer (NSCLC) or small cell lung cancer (SCLC). Eighty percent of lung cancer is NSCLC. SCLC tends to grow more quickly and is more likely to spread than NSCLC.