Lung cancer originates from the tissues of the lung, usually from cells lining the air passages. The two main types are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). These types are diagnosed based on how the cells look under a microscope. More than 80% of all lung cancers belong to the non-small cell type. The 3 major sub-types of non-small cell lung cancer are adenocarcinoma, squamous cell carcinoma and large cell carcinoma.
