Causes of Lung Cancer

Lung cancer most commonly begins in the cells that line your lungs. Smoking causes the majority of lung cancer — both in smokers and in people exposed to secondhand smoke. But lung cancer also occurs in people who never smoked. In these cases, there may be no clear cause of lung cancer. Doctors have identified factors that may increase the risk.

Cigarette smoking is known to be the cause of most lung cancers. Lung cancer can also develop in people who do not smoke, although this is much rarer. The risk of developing lung cancer increases with the number of cigarettes smoked, and if people started smoking at a young age. Filtered and low-tar cigarettes may slightly reduce a person’s risk of developing cancer, but the risk is still far greater than that of a non-smoker.

Lung cancer has always been more common in men, particularly those over 40, as more men used to smoke than women. However, as more women have started smoking, the number of women developing lung cancer has gone up considerably.

How smoking causes lung cancer ? Doctors believe smoking causes lung cancer by damaging the cells that line the lungs. When you inhale cigarette smoke, which is full of cancer-causing substances (carcinogens), changes in the lung tissue begin almost immediately. At first your body may be able to repair this damage. But with each repeated exposure, normal cells that line your lungs are increasingly damaged. Over time, the damage causes cells to act abnormally and eventually cancer may develop.

Your lungs are full of blood vessels and lymph vessels, giving lung cancer cells easy access to travel to other parts of your body. For this reason, lung cancer may spread to other parts of your body before you experience any signs or symptoms. In many cases, lung cancer may spread before it can even be detected in the lungs.

Other causes of lung cancer are:

1) Genetic Risk - In some families, smokers may be more likely to develop lung cancer due to inherited faulty genes. At present, we do not know what these genes are.

2) Asbestos - People who have been in prolonged or close contact with asbestos have a higher risk of lung cancer, especially if they smoke. Asbestos and tobacco smoke act together to increase the risk of lung cancer. Many people have been in contact with asbestos during their working lives. Low-level exposure increases the risk of lung cancer only slightly, compared to the risk from smoking, while heavy exposure may result in a much higher risk of lung cancer. Asbestos exposure also increases the risk of mesothelioma, a cancer of the membranes which cover the lungs.

If you have worked with asbestos and developed lung cancer, you may be able to claim compensation or be paid Industrial Injuries Disablement Benefit. You can get more advice about this from your cancer doctor or from support organisations.

3) Radon Gas - In some parts of the UK, such as the West Country and the Peak District, a naturally occurring gas called radon can pass from the soil into the foundations of buildings. It is now thought that this gas, in high concentrations, may increase the risk of developing lung cancer.