How is lung cancer diagnosed?
If a doctor suspects that you may have lung cancer, the common initial test is a chest x-ray. This is a simple and quick test, and may show changes such as abnormal shadowing. However, a chest x-ray cannot confirm cancer as there are various causes of shadowing on a chest x-ray. Other tests are needed.
Confirming the diagnosis
For all suspected cancers, it is best to confirm the diagnosis by getting a small sample or 'biopsy'. The biopsy sample is then examined under the microscope to look for the abnormal cells of cancer. The type of cancer can also be determined from the sample (and other causes of the symptoms or abnormal tissue ruled out.) One or more of the following procedures may be done to obtain a sample for testing.
- Bronchoscopy is the most common procedure to look into the airways and to obtain a biopsy from a tumour in a main airway. A bronchoscope is a thin, flexible, telescope. It is about as thick as a pencil. The bronchoscope is passed through the nose, down the back of the throat, into the windpipe (trachea), and down into the bronchi. The fibre-optics allows light to shine round bends in the bronchoscope and so the doctor can see clearly inside your airways. A bronchoscope has a side channel down which a thin 'grabbing' instrument can pass. This can be used to take a small biopsy from tissue on the the inside lining of a bronchi. (See separate leaflet called 'Bronchoscopy' for more details.)
- Sputum culture. You may be asked to collect some sputum (phlegm). Cancer cells can sometimes be seen by looking at sputum with a microscope.
- Fine-needle biopsy. This is where a doctor inserts a thin needle through the chest wall to obtain a small sample of tissue. X-ray pictures of the suspected tumour help the guide the doctor to insert the needle into a suspected tumour. The skin is numbed with local anaesthetic to make the test as painless as possible.
- Pleural tap. If you have an accumulation of fluid next to the lung which may be due to a tumour, some fluid can be drained with a fine needle (similar to the above). The fluid is examined for cancer cells.
- Mediastinoscopy. This is used to inspect and biopsy lymph nodes in the centre of the chest (the mediastinum). It is usually done under a general anaesthetic. An instrument similar to a bronchoscope is used. A small cut is made in the neck and the instrument is pushed down next to the trachea.
- Thoracoscopy. Sometimes an instrument similar to a bronchoscope is inserted through a cut in the chest wall. This is done under general anaesthetic. It enables a doctor so see and biopsy lung tissue directly.
Assessing the extent and spread
If you are confirmed to have lung cancer, further tests may be done to assess if it has spread. For example, a CT scan, an MRI scan, a bone scan, a PET scan, or other tests. (There are separate leaflets which describe each of these tests in more detail.) This assessment is called 'staging' of the cancer. The aim of staging is to find out:
- How much the cancer in the lung has grown.
- Whether the cancer has spread to local lymph nodes or to other areas of the lungs.
- Whether the cancer has spread to other areas of the body (metastasised).
By finding out the stage of the cancer it helps doctors to advise on the best treatment options. It also gives a reasonable indication of outlook (prognosis). See separate leaflet called 'Cancer Staging' for details.
What are the treatment options for lung cancer?
Treatment options which may be considered include surgery, chemotherapy and radiotherapy. The treatment advised for each case depends on various factors such the site of the primary tumour in the lung, the type of the cancer, the stage of the cancer (how large the cancer is and whether it has spread), and your general health.
You should have a full discussion with a specialist who knows your case. They will be able to give the pros and cons, likely success rate, possible side-effects, and other details about the various possible treatment options for your type of cancer.
You should also discuss with your specialist the aims of treatment. For example:
- Treatment may aim to cure the cancer. Some lung cancers can be cured, particularly if they are treated in the early stages of the disease. (Doctors tend to use the word 'remission' rather than the word 'cured'. Remission means there is no evidence of cancer following treatment. If you are 'in remission', you may be cured. However, in some cases a cancer returns months or years later. This is why doctors are sometimes reluctant to use the word cured.)
- Treatment may aim to control the cancer. If a cure is not realistic, with treatment it is often possible limit the growth or spread of the cancer so that it progresses less rapidly. This may keep you free of symptoms for some time.
- Treatment may aim to ease symptoms. Even if a cure is not possible, treatments may be used to reduce the size of a cancer which may ease symptoms such as pain. If a cancer is advanced then you may require treatments such as nutritional supplements, painkillers, or other techniques to help keep you free of pain or other symptoms.
Surgery
An operation may be an option if the cancer is in an early stage. Surgery usually involves removing part or all of an affected lung. However, in many cases, the cancer has already spread when it is diagnosed and surgery is not usually then an option. Also, surgery may not be an option if your general health is poor. For example, if you have other lung problems such as chronic obstructive airways disease (COPD) which is also common in smokers.
Radiotherapy and chemotherapy
There are separate leaflets which give more details about these treatments. Briefly:
- Radiotherapy is a treatment which uses high energy beams of radiation which are focussed on cancerous tumours. This kills cancer cells, or stops cancer cells from multiplying.
- Chemotherapy is a treatment of cancer by using anti-cancer drugs which kill cancer cells, or stop them from multiplying.
What is the prognosis (outlook)?
The outlook is best in those who are diagnosed when the cancer is still small, and has not spread. Surgical removal of a tumour in an early stage may then give a good chance of cure. However, most people with lung cancer are diagnosed when the cancer has already spread. In this situation a cure is less likely. However, treatment can often slow down the progression of the cancer.
The treatment of cancer is a developing area of medicine. New treatments continue to be developed and the information on outlook above is very general. The specialist who knows your case can give more accurate information about your particular outlook, and how well your type and stage of cancer is likely to respond to treatment.
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