Summary

Key Points

• Salivary gland cancer is a rare disease in which malignant (cancer) cells form in the tissues of the salivary glands.
• Being exposed to certain types of radiation may increase the risk of salivary cancer.
• Signs of salivary gland cancer include a lump or trouble swallowing.
• Tests that examine the head, neck, and the inside of the mouth are used to detect (find) and diagnose salivary gland cancer.
• Certain factors affect treatment options and prognosis (chance of recovery).

Salivary gland cancer is a rare disease in which malignant (cancer) cells form in the tissues of the salivary glands.

The salivary glands make saliva and release it into the mouth. Saliva has enzymes that help digest food and antibodies that help protect against infections of the mouth and throat. There are 3 pairs of major salivary glands:

• Parotid glands: These are the largest salivary glands and are found in front of and just below each ear. Most major salivary gland tumors begin in this gland.
• Sublingual glands: These glands are found under the tongue in the floor of the mouth.
• Submandibular glands: These glands are found below the jawbone.

There are also hundreds of small (minor) salivary glands lining parts of the mouth, nose, and larynx that can be seen only with a microscope. Most small salivary gland tumors begin in the palate (roof of the mouth).

More than half of all salivary gland tumors are benign (not cancerous) and do not spread to other tissues.

Salivary gland cancer is a type of head and neck cancer.

Risk Factors

Being exposed to certain types of radiation may increase the risk of salivary cancer.

Anything that increases the chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk with your doctor if you think you may be at risk. Although the cause of most salivary gland cancers is not known, risk factors include the following:

• Older age.
• Treatment with radiation therapy to the head and neck.
• Being exposed to certain substances at work.

Screening and Detection

Tests that examine the head, neck, and the inside of the mouth are used to detect (find) and diagnose salivary gland cancer.

The following procedures may be used:

Physical exam and history: An exam of the body to check general signs of health. The head, neck, mouth, and throat will be checked for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.

MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).

CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.

Endoscopy: A procedure to look at organs and tissues inside the body to check for abnormal areas. For salivary gland cancer, an endoscope is inserted into the mouth to look at the mouth, throat, and larynx. An endoscope is a thin, tube-like instrument with a light and a lens for viewing.

Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.

• Fine needle aspiration (FNA) biopsy: The removal of tissue or fluid using a thin needle. An FNA is the most common type of biopsy used for salivary gland cancer.
• Incisional biopsy: The removal of part of a lump or a sample of tissue that doesn’t look normal.
• Surgery: If cancer cannot be diagnosed from the sample of tissue removed during an FNA biopsy or an incisional biopsy, the mass may be removed and checked for signs of cancer.

Because salivary gland cancer can be hard to diagnose, patients should ask to have the tissue samples checked by a pathologist who has experience in diagnosing salivary gland cancer.

Signs and Symptoms

Signs of salivary gland cancer include a lump or trouble swallowing.

Salivary gland cancer may not cause any symptoms. It may be found during a regular dental check-up or physical exam. Signs and symptoms may be caused by salivary gland cancer or by other conditions. Check with your doctor if you have any of the following:

• A lump (usually painless) in the area of the ear, cheek, jaw, lip, or inside the mouth.
• Fluid draining from the ear.
• Trouble swallowing or opening the mouth widely.
• Numbness or weakness in the face.
• Pain in the face that does not go away.

Treatment Options

There are different types of treatment for patients with salivary gland cancer.

Different types of treatment are available for patients with salivary gland cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Patients with salivary gland cancer should have their treatment planned by a team of doctors who are experts in treating head and neck cancer.

Your treatment will be overseen by a medical oncologist, a doctor who specializes in treating people with cancer. Because the salivary glands help in eating and digesting food, patients may need special help adjusting to the side effects of the cancer and its treatment. The medical oncologist may refer you to other doctors who have experience and expertise in treating patients with head and neck cancer and who specialize in certain areas of medicine. These include the following:

• Head and neck surgeon.
• Radiation oncologist.
• Dentist.
• Speech therapist.
• Dietitian.
• Psychologist.
• Rehabilitation specialist.
• Plastic surgeon.

Three types of standard treatment are used:

Surgery

Surgery (removing the cancer in an operation) is a common treatment for salivary gland cancer. A doctor may remove the cancer and some of the healthy tissue around the cancer. In some cases, a lymphadenectomy (surgery in which lymph nodes are removed) will also be done.

Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given radiation therapy after surgery to kill any cancer cells that are left. Treatment given after surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Special types of radiation may be used to treat some salivary gland tumors. These include:

• Fast neutron radiation therapy: Fast neutron radiation therapy is a type of high-energy external radiation therapy. A radiation therapy machine aims tiny, invisible particles, called neutrons, at the cancer cells to kill them. Fast neutron radiation therapy uses a higher-energy radiation than the x-ray type of radiation therapy. This allows the radiation therapy to be given in fewer treatments.
• Photon-beam radiation therapy: A type of radiation therapy that reaches deep tumors with high-energy x-rays made by a machine called a linear accelerator. This can be delivered as hyperfractionated radiation therapy, in which the total dose of radiation is divided into small doses and the treatments are given more than once a day.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

See Drugs Approved for Head and Neck Cancer for more information. (Salivary gland cancer is a type of head and neck cancer.)

New types of treatment are being tested in clinical trials.

This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI Web site.

Radiosensitizers

Radiosensitizers are drugs that make tumor cells more sensitive to radiation therapy. Combining radiation therapy with radiosensitizers may kill more tumor cells.

Patients may want to think about taking part in a clinical trial.

For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.

Many of today’s standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Patients can enter clinical trials before, during, or after starting their cancer treatment.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI’s listing of clinical trials.

Follow-up tests may be needed.

Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests.

Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.