Lung Cancer
Lung Cancer is almost invariably associated with cigarette smoke. It is the commonest cancer in the developed world, with 40,000 cases arising each year in the UK. There are four different types, classified according to the cell type that they arise in. The most common is called a squamous cell carcinoma and it usually arises in cells of the bronchi. Less common is an adenocarcinoma, which arises in the lung tissue itself rather than the airways, and which is not necessarily related to smoking. There are two other types, called large cell and small or oat cell, which are named according to the cells they contain. The symptoms produced by cancer of the lung are commonly those caused by the growth itself affecting tissues around it: a persistent dry cough, haemoptysis (coughing up blood), shortness of breath (particularly if there has been collapse of part of a lung as a result of obstruction of the air way), or if there has been spread to lymph nodes which may press on other structures, such as the blood vessels draining the head and neck - the superior vena cava - causing swelling and congestion of the face. Besides symptoms caused by the physical presence of the cancer itself there may be associated symptoms of fatigue, loss of appetite and weight loss. Some tumours secrete hormone like chemicals which affect bones causing bone pain particularly at the wrists and ankles (called hypertrophic pulmonary osteoarthropathy). Lung cancer is one of the causes of clubbing of the fingers. Direct spread of the tumour to the bones causes localised bone pain which may respond to radiotherapy. Some tumours are treatable using surgery, but this is inappropriate in the many cases were the tumour has already spread. Radiotherapy and chemotherapy are both used, with variable success.
Besides cigarette smoking, there is an association with exposure to asbestos, and radon, which is a radioactive gas released by granite. The contribution, however, is minimal in comparison with that caused by smoking.
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