Lung cancer

Cigarette smoking is by far the most important single factor in causing lung cancer and is directly responsible for at least 90 per cent of lung cancers. The risk of lung cancer among current smokers is about fifteen times that for those who have never smoked; it is highest for heavy smokers and increases with more years of smoking. Despite the fact that the link between cigarette smoking and lung cancer was shown over 40 years ago, people still continue to smoke and in fact there is a steady rise in the number of lung cancer cases in women over the age of 55. The number of smokers was decreasing but has increased since 1994, particularly among young people and women under 35.

Cigarette smoke contains tar and thousands of other chemicals that irritate the lining of the lungs eventually causing changes in the cells of the lining which ultimately become cancer cells. Giving up smoking results in a gradual decline in the risk of developing lung cancer so that people who have smoked less than 20 cigarettes a day will, after 13 years of giving up smoking, have the same risk as someone who has never smoked.

There is also evidence that people who stop smoking even well into middle age will avoid more than 90 per cent of the risk of smoking. This is contrary to the belief of those smokers who say it is 'too late to give up now'.

A lot has been written about the role of passive smoking as a cause of lung cancer. There is increasing evidence that it does contribute to the development of this disease, some studies showing that passive smoking over a prolonged period can increase the risk by as much as two and a half times although the actual level of increased risk remains unproven.

Other causes of lung cancer include occupational and environmental factors such as exposure to radioactive minerals, fumes and high concentrations of radon gas in certain homes.

Unfortunately lung cancer can be difficult to diagnose in its early stages because often it does not cause any symptoms until later on in its development. Also many of the symptoms it causes are common to less serious illnesses such as bronchitis. The most common symptoms are a persistent or worsening cough, increasing breathlessness or coughing up blood. It may also cause chest pain unrelated to exercise, persistent shoulder pain, fatigue, loss of appetite and weight loss. Sometimes continuous wheezing or persistent hoarseness of the voice can be a sign of lung cancer.

The patient's own GP may strongly suspect the diagnosis of lung cancer simply from the symptoms and by listening to the chest. However, for a firm diagnosis to be made a chest x-ray is usually done in the first instance. If this seems to confirm the doctor's diagnosis a referral to a specialist will be made for further confirmatory tests.

These usually include a bronchoscopy (looking inside the lung with a special flexible telescope) or, if the tumour is near the edge of the lung, something called a CT guided percutaneous needle biopsy is done. This means that a special needle is inserted through the skin of the chest into the tumour under x-ray guidance to take a sample (biopsy) of the affected tissue. The specialist will always try to get a biopsy wherever the tumour is placed. This is partly so that a firm diagnosis can be made, but also because, as mentioned above, the exact type of lung cancer will help the doctors to decide on the precise type of treatment required.

Occasionally other tests will be done to determine if the cancer has spread to any other parts of the body. These tests may include liver biopsies or special scans of the bones, chest or abdomen.

The type of treatment given for lung cancer varies according to three main things:

• The type of cell causing the cancer (as described above)
• The extent of spread of the cancer
• The general condition of the patient

These factors will also help the doctors decide whether they are able to aim for a chance of complete cure, whether they are aiming to slow down the spread of the disease (because cure is unlikely) or whether the treatment is going to be palliative ie reducing the symptoms caused by the disease.

Surgery

This is usually only performed in a minority of patients with lung cancer. It is generally only done in those people who have the 'non-small cell' type of lung cancer, where the cancer has been diagnosed at an early stage, if the cancer can be fully removed and the individual is well enough to withstand the major surgery involved. This usually requires removal of part of the lung affected (called a 'lobectomy') or sometimes removal of the whole lung (pnuemonectomy). In these situations surgery can cure the problem but unfortunately very few people fall into this category.

Radiotherapy (X-ray treatment)

This is generally given either after or instead of surgery as a way of preventing the spread of the disease. Typically a course lasting three to six weeks will be given.

Chemotherapy

This involves treatment with powerful anti-cancer drugs often given directly into the veins. Patients are usually treated in hospital but as day patients, going home between each session of treatment. This is because the treatment courses are generally separated by a few weeks to allow the body to recover. Chemotherapy is especially effective for small cell lung cancer.

Surgery for lung cancer involves a major operation so recovery can be slow. Side effects include pain at the site of the operation in the side of the chest that can continue for a long time after the operation and the removal of part or all of the lung can cause a certain amount of breathlessness.

Radiotherapy can cause sickness, diarrhoea, loss of appetite and soreness of the oesophagus (swallowing tube). Also a type of inflammation of the lung called pneumonitis can result from radiotherapy although this can normally be treated with steroids.

Chemotherapy can also cause nausea and vomiting though frequently drugs can be given to try to control this side effect. Unfortunately hair loss is a common side effect of chemotherapy although the hair usually re-grows a few months after treatment has been completed. Anti-cancer drugs can also sometimes lead to a reduction in the number of protective white blood cells in the bloodstream making the individual more open to infection, so the doctors monitor the blood count during chemotherapy treatment and treat any sign of infection with antibiotics.

Palliative treatment means treatment designed to relieve symptoms. Nowadays therapies exist which can control most symptoms related to serious illnesses such as lung cancer. For instance radiotherapy can be used in certain cases to relieve symptoms such as a troublesome persistent cough, coughing up blood or even pain in the bones from spread of the tumour to the skeleton. Pain can also be controlled by a number of different drugs of varying strengths.

The whole area of what is now known as palliative medicine has progressed greatly in recent years so that most sufferers of lung cancer can have access to care and advice from specially trained cancer nurses who are often based in a hospice where residential palliative care can be given in a homely environment.

The role of genetics in the formation and treatment of lung cancer is an area which is only beginning to be understood but which promises possible new treatments for lung cancer. In the near future, genetic studies of individuals with the condition may help doctors to identify which patients will respond to which type of treatment. Also the very latest research indicates that there may be certain people with a gene which protects against lung cancer raising the possibility in the future of a vaccine against the disease although this is some way off.

Apart from contacting your GP, the following organisations may be of further help:

Macmillan Cancer Support
89 Albert Embankment
Londin
SE1 7UQ
Telephone: 0808 808 00 (Freephone Helpline 09:00 to 20:00)
Website: www.macmillan.org.uk

The British Lung Foundation
73-75 Goswell Road
London
EC1V 7ER
Telephone: 02076 885555 (Helpline Monday to Friday 10am - 6pm)
Website: www.lunguk.org/

Hospice Information Service
Hospice House
Help the Hospices
34-44 Britannia Street
London
WC1X 9JG
Telephone: 0207 520 8222 (Mon to Fri 09:00 to 17:00)
Website: www.helpthehospices.org.uk

Roy Castle Lung Cancer Foundation
The Roy Castle Centre
4-6 Enterprise Way
Wavertree Tech Park
Liverpool
Merseyside
L13 1FB
Telephone: 0151 254 7200