What is Lung Cancer?
Lung cancer is the most common type of cancer, with 1.8 million new cases in 2012 worldwide.1 There are two main types of lung cancer – small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) – which are treated very differently.2
- SCLC accounts for 10–15% of lung cancers, and is named for the small size of the cells seen under the microscope. It is usually caused by smoking, and tends to spread quite early on.2
- NSCLC is the most common type of lung cancer, making up the remaining 80–85% of cases.2 There are three main types of NSCLC – adenocarcinoma (40%), squamous cell carcinoma (25–30%) and large cell carcinoma (10–15%).2 They look different under the microscope, but are grouped together because doctors treat them in a similar way.2
- Adenocarcinoma develops from the mucus-producing cells in the lining of the airways, usually in the peripheral regions of the lung, and is generally slow-growing.2
- Squamous cell carcinoma arises in the cells covering the surface of the airways. These tumours are often found in the central areas of the lung.2
- Large cell carcinoma can develop in any area of the lung. It tends to grow and spread quickly.2