Salivary Gland Cancer

What are the salivary glands?

The salivary glands make spit (saliva) and releases it into the mouth to keep the mouth and throat moist, and help with swallowing and digesting food.

There are major (large) and minor (small) salivary glands. There are three pairs of major salivary glands: the parotid gland, submandibular glands and sublingual glands.

Parotid Gland

The parotid glands are found just in front of the ears and behind the jaw. They move saliva into the mouth through a tube called the parotid duct. This tube opens on the inside of the cheek, near the upper molar teeth. The nerve that controls the facial muscles (called the facial nerve), runs through the parotid gland. This nerve makes you smile, frown, close your eyes and raise your eyebrows.

The parotid gland is the largest salivary gland and where most Salivary Gland Cancers occur.

The parotid glands also contain lymph nodes (bean shaped glands that are part of the immune system’s defence against infections). Sometimes skin cancers, can spread to the lymph nodes inside the parotid glands. Most parotid gland tumours are not cancers and are called benign tumours.

Submandibular and Sublingual Glands

The submandibular glands lie under the jawbone, one on each side. They release saliva into the mouth through a duct (tube) that opens in the floor of the mouth, under the tip of the tongue. Three important nerves are found next to these glands –the hypoglossal nerve, lingual nerve and marginal branch of the facial nerve. These nerves give movement, feeling and taste to the tongue and move the lower lip. Tumours of the submandibular gland can be benign (not cancer) or malignant (cancer).

The sublingual glands lie under the tongue, one on each side. They release saliva into the submandibular duct and are near the lingual nerves which give feeling and taste to the front of the tongue. The sublingual glands are the smallest of the major salivary glands and rarely develop tumours, but tend to be malignant (cancer) when they do develop.

Minor Salivary Glands

There are hundreds of minor salivary glands throughout the mouth and throat. They can be found inside the mouth, just under the surface including the lips, cheeks and top of the mouth (soft palate). The minor salivary glands can also develop tumours, which can be benign or malignant.

Diagram of the salivary glands and surrounding areas:

What Causes Salivary Gland Cancer?

Doctors often can’t explain why a person gets cancer. However, factors that may increase the risk of Salivary Gland Cancer include:

• Age - most Salivary Gland Cancers occur in people aged over 50 years
• Exposure of the head and neck to radiation therapy
• Autoimmune diseases – these can lead to a type of cancer in the salivary glands called lymphoma
• Skin Cancers can spread to lymph nodes in the salivary glands

Other factors, such as using mobile phones and exposure to industrial chemicals, have not been proven to increase the risk of Salivary Gland Cancer.

The signs and symptoms of Salivary Gland Cancer depend on where the cancer is, its size, and how far it has spread in the body.

Common signs and symptoms include:

• a lump in front of the ear or in the neck
• drooping on one side of the face
• numbness in the face
• a lump or sore inside the mouth that does not go away
• trouble swallowing or opening the mouth widely.

Most of these are also signs and symptoms of other conditions. However, if you have any of these symptoms for more than a few weeks, speak with your doctor as early as possible. They may be able to help diagnose and treat you.

Following a diagnosis of Salivary Gland Cancer, your cancer care team will discuss treatment options that are suitable for you. This is also a good time to consider if you would like a second opinion.

The most suitable treatment of Salivary Gland Cancer depends on many things. These include:

• type and grade of Salivary Gland Cancer
• size and location of the cancer
• whether it has spread
• personal factors (e.g. age, general health and treatment history)
• treatments available (and whether any clinical trials are available)
• your preferences for treatment.

Surgery is often the main treatment for Salivary Gland Cancer. This involves cutting the cancer out and, for some patients, taking out the lymph nodes.

A week or two after surgery, your pathologist will give a detailed report on the cancer. This will be used by your cancer care team to decide if you need more treatment to reduce the risk of the cancer coming back. This treatment may be radiation therapy alone or radiation combined with chemotherapy (chemoradiation) and, occasionally, it may be radiation therapy followed by chemotherapy.

Adding another treatment after surgery is called adjuvant therapy. Adjuvant therapy usually starts about 4–6 weeks after surgery so that you have time to recover from your surgery. Adjuvant therapy usually lasts for about 6 weeks.

• Low-grade cancer is usually treated with surgery alone and, usually, the lymph nodes do not need to be removed.
  
  
• High-grade cancer usually involves removing the lymph nodes during surgery and adjuvant radiation therapy after surgery. Sometimes chemotherapy is added, however, this will depend on the features of the cancer, your cancer care team and, sometimes, what clinical trials are available.

Salivary Gland Cancer can cause physical changes while its treatment can cause side effects. Some of these physical changes and side effects will go away soon after treatment, while others may be long-term or permanent.

How Can I Prepare for the Surgery?

Your doctor will explain details of the surgery, general risks and side effects of surgery. Ask your doctor if you have questions. They may recommend:

• stopping blood thinners (e.g. aspirin) before surgery to reduce the risk of bleeding
• special stockings to reduce the risk of blood clots
• early mobilisation (i.e not staying in bed) to reduce the risk of blood clots and chest infection
• antibiotics to lower the risk of wound infection.

Before starting treatment, it is important that you consider stopping smoking to reduce the risk of infection and help you fully recovery after your treatment.

Radiation Therapy for Salivary Gland Cancer

The most common approach of radiation therapy for Salivary Gland Cancer is called external beam radiation. This type of radiation therapy applies radiation from outside the body.

Radiation therapy can be used in the following ways:

Definitive
This is when radiation therapy is used on its own without surgery to cure Salivary Gland Cancer. It is used in Salivary Gland Cancer when surgery is not a treatment option.

Adjuvant
This is when radiation therapy is given after surgery, to kill cancer cells that may not have been taken out during surgery. It can be used either on its own or at the same time as chemotherapy (chemoradiation), to make it more effective. The decision to give radiation therapy, either alone or with chemotherapy, is based on the pathology results after surgery. The aim of adjuvant radiation therapy is to reduce the risk of Salivary Gland Cancer coming back. Not everyone will require adjuvant radiation therapy.

Palliative
In cases where a cure is not possible, radiation therapy is used to relieve symptoms of advanced Salivary Gland Cancer. Symptoms that may require palliative radiation therapy include pain, bleeding, breathing and trouble swallowing.

How do I Prepare for Radiation Therapy?

You will meet with many members of the cancer care team, who will help you learn how to look after yourself through radiation therapy, recovery and long term follow-up. They will also talk to you about side effects and how to manage them. It may be helpful to write down questions as they come up, so you can ask anyone in your cancer care team when you see them.

Radiation Therapy Mask-Making and Simulation

• Radiation therapy is a precise treatment. In order to make sure, that the cancer is covered by the treatment, you will need to be very still during the treatment, usually for about five minutes. A radiation therapy mask that is made to fit perfectly to your shape, will be put on you during each treatment to help the machine target where the cancer is.
• You will have a planning CT scan (and sometimes other scans) with the mask on. Your radiation oncologist and radiation therapists will use these scans with all your other clinical information to develop a radiation therapy plan just for you (a personalised plan). Your plan will be checked by the radiation therapy and radiation oncology physics team before it is ready to be used for your treatment. This whole process can take approximately 2-3 weeks.

Teeth and Mouth Care

You might need to have some of your teeth taken out, this will depend on the area being treated and the dose of radiation therapy. It is important to take out any broken or infected teeth before radiation therapy. Taking out unhealthy teeth after radiation therapy can cause problems with the jaw bone. Further information about removing teeth and teeth and mouth care can be found here.

Diet, Nutrition and the Role of your Dietitian

Your cancer and its treatment can make it hard to eat and drink. Your doctor will recommend you see a dietitian to maximise your nutrition during treatment as well as while you are recovering. Sometime feeding tubes may be recommended depending on the area being treated and the dose of radiation therapy.
There are two common types of feeding tubes:

• Gastrostomy tube (sometimes called a PEG tube): this type of tube is inserted through your abdominal wall into your stomach, with part of the tube staying outside the stomach. A syringe can be attached to the tube to give you food this way if needed. The tube is inserted using a camera through the mouth into the stomach (gastroscopy) or using a CT scanner to guide insertion directly through the skin. If a PEG tube is needed, your doctor will organise this before starting your radiation therapy
  
  
• Nasogastric tube: this type of tube goes through the nose down into the stomach and is usually used for short periods (days or weeks). A nasogastric tube can be inserted at any time (before, during or after treatment).

Speech, Voice and Swallowing

Your cancer and its treatment can make swallowing and speech difficult. Your doctor will recommend you see a speech pathologist, who can help you with ways to manage swallowing and communication difficulties, during and after treatment.

There are many other aspects of supportive care that are available, ask your doctor if you have any specific needs.

Side Effects

The side-effects of radiation therapy start around two weeks into treatment and progress through treatment to peak in the last week or just after treatment ends. The side effects start to improve 2-3 weeks after the end of treatment.

Side effects associated with radiation therapy depend on:

• the dose of radiation therapy
• the area being treated
• whether or not chemotherapy is added to the radiation.

Each individual responds to radiation therapy differently. Some people may experience a few side effects while others may not experience any at all. The following are some common side effects of radiation therapy.

Common side effects of radiation therapy include:

• tiredness
• skin irritation in the treated area e.g. redness, dryness and itching, weeping skin, scaling or sometimes skin breakdown (sores)
• dry mouth or throat due to lack of saliva (called xerostomia)
• ulcers in the mouth or throat that make it painful or difficult to chew or swallow
• sticky or thick saliva
• altered taste, which is usually a loss of taste or sometimes an unpleasant taste in the mouth
• weight loss
• blocked ears from inflammation within the ear canals.

Most side effects are short lived and may go away within 4–6 weeks of finishing radiation therapy. Some side effects may last for months after you finish radiation therapy and some may be permanent.

Once your radiation therapy ends, you will have regular follow-up appointments so your cancer care team can check your recovery and monitor any side effects that you may have. Your doctor may recommend some specific supportive care options to help during your recovery, such as help with changes in diet, teeth and mouth care and speech or swallowing.

Chemotherapy for Salivary Gland Cancer

Chemotherapy works by destroying or damaging cancer cells. For Salivary Gland Cancer, it is usually given into a vein through a needle with a cannula (tube) attached.

There are a number of ways that chemotherapy may be used to treat Salivary Gland Cancer including:

Adjuvant
This is when chemotherapy is given after surgery and is usually combined with radiation therapy (chemoradiation). It is usually given once a week during radiation therapy. Adding chemotherapy makes the radiation more effective at destroying cancer cells, but also leads to increased side effects for most patients

Neo-adjuvant
This is when radiation therapy is given before surgery or radiation therapy. It is used to shrink large cancers so they are easier to remove during surgery or target with radiation therapy. Neoadjuvant chemotherapy is rarely used for Salivary Gland Cancer.

Palliative
This is given when the cancer is incurable, because the cancer is too big or has spread too far to be removed by surgery. Even if a cancer is incurable, some patients feel better from palliative chemotherapy as it slows the growth of the cancer, and can relieve or prevent symptoms.

Before you start treatment, your medical oncologist will choose one or more chemotherapy medications that will be best to treat the type of cancer you have.

The chemotherapy medications your doctor chooses may depend on:

• whether the treatment is curative or palliative
• when it is used
• your medical history

Side Effects

The side effects of chemotherapy depend on the medication used and its dose. The most common medications used are called cisplatin, carboplatin and fluorouracil (5-FU).

Each individual responds to chemotherapy differently. Some people may experience a few side effects while others may not experience any at all.

The following are common side effects of chemotherapy:

• ulcers on the lining of the mouth and throat
• a feeling of wanting to vomit (nausea) and vomiting
• loss of feeling in the fingers and toes
• ringing in the ears (tinnitus), or hearing loss
• rash
• change in taste
• hair loss or thinning
• higher risk of infection (if the chemotherapy reduces the number of white cells in the blood)
• low levels of red blood cells, sometimes requiring a blood transfusion.

Most of these side effects are short lived and go away once you finish chemotherapy. Some side effects like hearing loss, may be permanent.

Once your treatments end, you will have regular follow-up appointments so that your doctor can check your recovery, make sure the cancer has not returned and monitor and treat any side effects that you may have. Your doctor may recommend that you receive some specific supportive care to help during your recovery.