Lung cancer is an uncontrolled growth of cells that start off in the lungs. Instead of developing into healthy lung tissue, the cells divide rapidly and forms malignant tumours. These malignant tumours develop in the cells of the lungs is known as lung cancer. Usually, lung cancer starts in the cells that line the air passages and it can also spread to other parts of the body.

There are two types of lung cancers based on cell size:-

• Small cell lung cancer (SCLC)
• Non-small cell lung cancer (NSCLC).