Types of Lung Cancer
There are two main types of lung cancer: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Approximately 75-80% of presenting cases are NSCLC, and 20-25% SCLC.
Small Cell Lung Cancer
SCLC may have neuroendocrine features as it is thought to arise from cells derived from the neural crest, but separate neuroendocrine tumours may also arise in the lungs, such as malignant carcinoid tumours.
Non Small Cell Lung Cancer
NSCLC is divided into several subtypes, squamous cell carcinomas, adenocarcinomas, undifferentiated cercinomas and large cell carcinomas. There are also subgroups within these classifications, such as bronchoalveolar carcinoma, a well-differentiated adenocarcinoma with a particular intra-alveolar distribution. Squamous cell carcinomas are the largest subgroup in the UK.
Overall, the differences within the groups are small and all subgroups of NSCLC are generally treated in the same way, and are therefore grouped together.
Mesotheliomas can be divided into three main histological types of lung cancer: epithelial, sarcomatous and mixed. The epithelial type is the most common, probably occurring in about two-thirds of cases, and the sarcomatous type is less common but associated with a more aggressive pattern of disease.