There are two main types of lung cancer and they are treated differently.
- small cell lung cancer (SCLC)
- non-small cell lung cancer (NSCLC)
In mixed small cell/large cell cancer, features of both are present.
What is non-small cell lung cancer (NSCLC)?
The majority of lung cancers are of the non-small cell type. There are three sub-types:
- squamous cell carcinoma is linked to smoking and usually found in the middle of the lungs, near a bronchus.
- adenocarcinoma is usually found in the outer part of the lung.
- large-cell (undifferentiated) carcinoma can start in any part of the lung. It tends to grow and spread quickly, which makes it harder to treat.
What is small cell lung cancer (SCLC)?
About 10% of all lung cancers are SCLC, also known as oat cell carcinoma. Although the cancer cells are small, they can multiply quickly and form large tumours that can spread widely. This means that surgery is rarely an option. Treatment must include drugs to kill the widespread disease. This kind of cancer is almost always caused by smoking.
Along with the two main types of lung cancer, other tumours can be found in the lungs. Sometimes cancer that starts in other organs can spread to the lungs and this is not the same as lung cancer. For example, cancer that starts in the breast and spreads to the lungs is still breast cancer, not lung cancer.