Lung cancer originates from the tissues of the lung, typically in the cells lining the air passages. The two main types of lung cancer are: small-cell lung cancer and non-small
cell lung cancer. They are diagnosed based on how the cells look under a microscope.
Non-small cell lung cancer is more common and includes squamous cell carcinoma,
adeno carcinoma, and large cell carcinoma. Small cell lung cancer is rarer but tends to
be aggressive and difficult to find until it has already spread (especially to the brain).
People who smoke are at greater risk of developing lung cancer than people who do not. The risk of lung cancer increases with the length of time and number of cigarettes you have smoked. If you quit smoking, even after smoking for many years, you can significantly reduce your chances of developing lung cancer.
Signs and symptoms of lung cancer typically occur when the disease is in an advanced stage. It is the most common cancer In India and is the leading cause of cancer-related mortality in men.