This information is about salivary gland cancer. You may find it helpful to read it alongside our general information about cancers of the head and neck, which discusses the treatments and their effects in more detail.

The salivary glands make saliva (spit). This keeps your mouth moist and helps food to slide down the gullet, into the stomach. The largest salivary glands are the:

• sublingual glands – found underneath the tongue
• parotid glands – at the sides of the mouth just in front of the ears
• submandibular glands – under the jawbone.

There are also many more tiny glands in the lining of the mouth and throat. These do not have individual names but are known as the minor salivary glands.

Cancers affecting the salivary glands are rare. Approximately 550 new cases of salivary gland cancer are diagnosed in the UK each year. They can occur at any age, but are more common in people over 50.

There are different types of salivary gland cancer, depending on the type of cell that has become cancerous.

Like many other forms of cancer, the exact causes are unknown. Non-cancerous (benign) tumours of the salivary glands are more common than cancerous (malignant) tumours.

Tumours affecting the salivary glands are not infectious, and can't be passed on to other people. They are not caused by an inherited faulty gene, so the relatives of someone with salivary gland cancer aren't likely to develop it.

The most common symptom of salivary gland cancer is a swelling on the side of the face, just in front of the ears, or under the jawbone. Some people also have some numbness and drooping of one side of the face (facial palsy).

These symptoms may occur with conditions other than cancer, and most people with these symptoms will not have a salivary gland cancer. However, like most cancers, salivary gland cancers are best treated when diagnosed at an early stage. You should report any of the above symptoms to your GP if they do not improve over a few days.

Your GP will examine you and arrange for any tests that may be necessary. You will need to be referred to a hospital specialist for these tests, and for expert advice and treatment. The specialist at the hospital will ask about your general health and any previous medical problems, before examining you. They may arrange blood tests to check your general health. The following tests are commonly used to diagnose salivary gland cancer:

CT (computerised tomography) scan This is a sophisticated type of x-ray which builds up a detailed three-dimensional picture of the inside of the body. The scan is painless but takes about 15 minutes. It may be used to identify the exact size of the tumour, or to check for any spread of the cancer. Most people who have a CT scan are given a drink or injection of a fluid that allows particular areas to be seen more clearly. If you are allergic to iodine or have asthma it is important to tell the person doing this test before you have the injection.

MRI (magnetic resonance imaging) scan This type of scan uses magnetism instead of x-rays to form a series of cross-sectional pictures of the inside of the body. During the scan you will be asked to lie very still on a couch inside a metal cylinder. You will usually be given an injection to allow the picture to be seen more clearly. The test can take up to an hour and is completely painless. If you don't like enclosed spaces you may find the machine claustrophobic. The machine is also quite noisy, but you will be given earplugs or headphones to wear.

Biopsy The doctor may use a fine needle and syringe to take a sample of cells from the affected area, to examine under a microscope. Alternatively, a small piece of tissue may be taken from the area. This procedure is usually performed under either a general or local anaesthetic.

Staging

The stage of a cancer is a term used to describe its size and whether or not it has spread beyond its original site. Knowing the particular type and the stage of the cancer helps the doctors to decide on the most appropriate treatment for you.

Cancer can spread in the body, either in the bloodstream or through the lymphatic system. The lymphatic system is part of the body's defence against infection and disease. The system is made up of a network of lymph glands (or nodes) that are linked by fine ducts containing lymph fluid. Your doctors will usually look at the lymph nodes close to the salivary glands, in order to assess the stage of your cancer.

The most commonly used staging system is called the TNM system.

• T refers to the tumour size.
• N refers to whether or not lymph nodes are affected.
• M refers to whether or not the cancer has spread to other parts of the body (metastases).

Tumour size (T)

• T1 The cancer is no bigger than 2cm in size and has not begun to spread.
• T2 The cancer is 2–4cm in size but has not begun to spread.
• T3 The cancer is bigger than 4cm and may have spread into nearby soft tissue.
• T4a The cancer is of any size, but it has spread to the skin, jaw-bone, ear-canal or facial nerves.
• T4b The cancer is of any size, but it has spread to other nearby bones, the base of the skull or the carotid artery.

Lymph nodes (N)

• N0 None of the lymph nodes are affected.
• N1 The cancer has spread to one lymph node on the same side of the neck as the tumour. The affected node is 3cm or smaller.
• N2a The cancer has spread to one lymph node on the same side of the neck as the tumour. The node is 3–6cm in size.
• N2b The cancer has spread to more than one lymph node on the same side of the neck as the tumour. None of them are larger than 6cm in size.
• N2c The cancer has spread to one or more lymph nodes on both sides of the neck, or on the opposite side to the tumour. None of the nodes are larger than 6cm in size.
• N3 The affected lymph nodes are larger than 6cm in size.

Metastases (M)

• M0 The cancer has not spread to other parts of the body.
• M1 The cancer has spread to other parts of the body such as the lungs.

Grading

Grading refers to the appearance of the cancer cells under the microscope, and gives an idea of how quickly the cancer may develop. Low-grade means that the cancer cells look very like normal cells; they are usually slow-growing and are less likely to spread. In high-grade tumours the cells look very abnormal, are likely to grow more quickly, and are more likely to spread.

Salivary gland cancers can start in various cells within the salivary glands and may be slow- or fast-growing. The type of treatment given will depend on a number of things, including the position of the cancer, the exact type of cancer, and your general health. The following treatments may be used alone or in combination with one another.

Surgery

Surgery may be used to remove the salivary gland. Your doctor will discuss the operation with you beforehand and will tell you about any possible side effects. The doctor may sometimes recommend surgery to remove any affected lymph nodes in the neck. There is a network of lymph nodes (lymph glands) throughout the body and they form part of the body's natural defence against infection. The lymph nodes are connected by a network of fine tubes known as lymph vessels.

Radiotherapy

Radiotherapy may be used to treat salivary gland cancers. Radiotherapy uses high-energy rays to destroy cancer cells, while doing as little harm as possible to normal tissue. During and after radiotherapy treatment to the salivary glands, your salivary glands will produce less saliva and this may affect your eating. It is important to see a dentist regularly if you have a dry mouth.

Keeping your mouth clean is very important, and your doctors and nurses will advise you about this. It can be helpful to visit a dentist before starting radiotherapy to make sure your mouth is as healthy as possible. This can help to prevent side effects developing in the future. If you need to have any teeth removed before treatment you should wait at least two weeks before starting radiotherapy to the salivary glands. If it is necessary to have a tooth removed after treatment this should be done by a hospital specialist.

Side effects of radiotherapy usually decrease gradually once the treatment has ended. Some people find that their salivary glands are permanently altered. It is important to discuss this with your doctor and dentist as it is often possible to find ways of reducing any problems. Your doctor or a dietitian at the hospital may be able to give you further advice if this problem occurs.

Chemotherapy

This is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. Although helpful for many types of cancer, chemotherapy is not very effective in treating salivary gland cancers and is used only occasionally.

You may be offered chemotherapy as part of a research trial. Before any trial is allowed to take place it must have been approved by the ethics committee, which checks that the trial is in the interest of patients.

You may be asked to take part in a clinical trial. Your doctor must discuss the treatment with you so that you have a full understanding of the trial and what it involves. You may decide not to take part, or to withdraw from a trial at any stage. You will then receive the best standard treatment available.

You will have regular check-ups once your treatment has finished. These will often continue for several years, frequently at first and then less often. Let your doctor know if you have any problems or notice any symptoms between visits.

During your treatment you are likely to experience a number of different emotions, from shock and disbelief to fear and anger. At times emotions can be overwhelming and hard to control. These feelings are quite natural. It is important, to be able to express them.

Each individual has their own way of coping with difficult situations; some people find it helpful to talk to friends or family, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is available if you need it. You may wish to contact our cancer information nurse specialists about counselling in your area.

This section has been compiled using information from a number of reliable sources, including:

• Improving Outcomes in Head and Neck Cancers. National Institute for Health and Clinical Excellence (NICE). November 2004.
• Oxford Textbook of Oncology (2nd edition). Eds Souhami et al. Oxford University Press, 2002.
• Cancer and its Management (5th edition). Eds Souhami and Tobias. Oxford Blackwell Scientific Publications, 2005.
• The Textbook of Uncommon Cancers (3rd edition). Eds Raghavan et al. Wiley, 2006.
• Cancer: Principles and Practice of Oncology (7th edition). Eds DeVita et al. Lippincott, Williams and Wilkins, 2005.

For further references, please see the general bibliography.