2. Lung cancer

There are more than 38,000 new cases of lung cancer in the UK every year. It's always been more common in men, particularly those over 40. However, recently, the number of women with the disease has increased considerably and it now claims more lives than breast cancer.

Lung cancer isn't infectious and can't be passed on to other people.

This article deals with primary lung cancer - when the cancer has started in the lung. It shouldn't be confused with secondary lung cancer - when cancer in another part of the body spreads to the lung.

Causes:

Cigarette smoking is the cause of nearly all lung cancers. The risk increases with the number and type of cigarettes smoked. See the damage smoking does to your body with the interactive Body tour.

Although lung cancer is rare among non-smokers, exposure to passive smoke (inhalation of other people's cigarette smoke) can be a cause.

Pipe and cigar smokers have a lower risk than cigarette smokers, but it's still a far greater risk than that of non-smokers.

Exposure to certain chemicals and substances, such as asbestos, uranium, chromium and nickel, have all been linked to lung cancer, but these are very rare causes. Contact your local environmental health officer if you're concerned.

Symptoms:

If you have the following, or any other symptoms, you must have them checked by your doctor. But remember, all occur in many conditions other than cancer.

• a persistent cough or change in the nature of a long-standing cough

• shortness of breath

• coughing up blood-stained phlegm (sputum)

• chest discomfort - a dull ache or sharp pain when you cough or take a deep breath

• loss of appetite and weight

Diagnosis:

At present there's no effective screening test for lung cancer. If you suspect you have any of the symptoms mentioned, see a GP immediately. Initial tests will include a chest x-ray. You may also be asked to bring samples of phlegm for examination.

There are several tests that can be done to diagnose lung cancer and these include:

• Bronchoscopy - a thin flexible tube is passed gently through your nose or mouth and into the lung airways. Photographs and cell samples are then taken.

• Mediastinoscopy - a small cut is made through the skin at the base of the neck under general anaesthetic. A tube is then passed into the chest, allowing the doctor to examine the area at the centre of the chest and local lymph nodes.

• Lung biopsy - a needle is passed through the skin into the lung and a sample of cells is taken for examination.

Treatment:

There are two main types of lung cancer - around a quarter are rapidly spreading small-cell lung cancers (SCLC); the remainder are relatively slow-growing non-small-cell lung cancers (NSCLC).

When the tumour is away from the centre of the chest and there's little or no spread (NSCLC), surgery is often used. A small part of the lung may be removed (wedge resection), or a lobe of the lung (lobectomy) or an entire lung (pneumonectomy).

Chemotherapy and/or radiotherapy are usually more effective in treating SCLC because this type of cancer rarely occurs in one place.

Sometimes lung cancer causes breathlessness by obstructing the wind pipe or one of the main airways. In such cases laser therapy can provide some relief.

You can breathe normally with only one lung. However, if you had breathing difficulties before the operation you may be more breathless afterwards. Breathing tests will be carried out to help you and your doctor decide on the best course of action.

New ways of treating lung cancer are being studied. In NSCLC cases, different ways of giving radiotherapy and chemotherapy are being investigated.