There are 2 main types of lung cancer:
Non-small cell lung cancer
Most cases of lung cancer are called non-small cell. There are a few different types of non-small cell lung cancer. These include squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.
Small cell lung cancer
Small cell lung cancer is less common than non-small cell lung cancer. Small cell cancer is sometimes called oat cell cancer. (The cells are shaped like oats when viewed under a microscope.) This type of lung cancer may grow and spread faster than non-small cell cancer.
How cancer spreads
Cancer cells don’t always stay in one place. Cancer cells can break off from the place they started. They can spread to other parts of the body if they enter the bloodstream. They can also spread if they enter the lymph system. The lymph system is a network of nodes and vessels that help your body fight disease. When cancer spreads, the process is called metastasis. Lung cancer that spreads (metastasizes) often goes to the other lung or the liver, brain, or bones.