What is lung cancer?

Lung cancer is a malignant growth of cells of the lungs, usually the cells lining the airways. The main cause of lung cancer is inhaling carcinogens in cigarette smoke, although there are other causes which include occupational exposure to asbestos. There are many different types of lung cancer including squamous cell carcinoma, adenocarcinoma, large cell and small cell lung carcinoma.

Main lung cancer types

Although there are many named types of lung cancer they can usefully be placed in two categories, these are -:

• Small cell lung cancer – small cell type seen on examination under the microscope
• Non-small cell lung cancer – any other type of lung cancer cell seen under the microscope – this includes adenocarcinoma, squamous cell carcinoma and any other type of lung cancer cell

This distinction is important as small cell or non-small cell type determines treatment and survival. In this guidance lung cancer will be split into these two cell types. Within each cell type each cancer can be split into 2 or 3 different groups based on stage of disease likely treatment needed, disabling effects and outcome. For those stages with poor survival chances, only survival figures will be presented as these cases will be terminally ill. For those expected to survive more than 6 months both survival chances and more detailed treatment options and disabling effects will be described.

Incidence and Prevalence

Lung cancer affects some 37 500 people a year in the UK and is the commonest killing cancer having a 5 year survival of about 10%.

At the time of diagnosis, only 10-15% of cases have localised disease. Of these with potentially treatable disease, half will have died within 5 years, despite potentially curative surgical resection. Over half of patients have metastatic disease by the time of diagnosis.

Amended June 2008