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 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.

Most salivary gland tumors in children are benign (not cancerous) and do not spread to other tissues. Some salivary gland tumors are malignant (cancer). Malignant tumors are more common in young children. The prognosis for salivary gland cancer in children is usually good.

A history of past treatment for cancer may increase the risk of salivary gland cancer.

Anything that increases your 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 child's doctor if you think your child may be at risk.

Risk factors for salivary gland cancer in children include past treatment for leukemia, lymphoma, sarcoma, or other cancers using:

• Chemotherapy.
• Radiation therapy to the neck or whole body.

Signs and symptoms of salivary gland cancer include a lump near the ear, cheek, jaw, or lip, or inside the mouth.

These and other signs and symptoms may be caused by salivary gland cancer or by other conditions.

Check with your child's doctor if your child has any of the following:

• A lump that may be painless near the ear, cheek, jaw, or lip, or inside the mouth.
• Numbness or weakness in the face.
• Pain in the face that does not go away.

Tests that examine the mouth and throat are used to diagnose salivary gland cancer.

The following tests and procedures may be used:

• Physical exam and health history: An exam of the body to check general signs of health, including checking 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 of the body, such as the head and neck. This procedure is also called nuclear magnetic resonance imaging (NMRI).
• PET-CT scan: Sometimes a PET scan and a CT scan are done at the same time. If there is any cancer, this increases the chance that it will be found.
  • 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.
• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later.
• 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 biopsy: The removal of tissue or fluid using a thin needle.

The process used to find out if cancer has spread from the salivary glands to nearby areas or to other parts of the body is called staging. There is no standard staging system for childhood salivary gland cancer. The results of the tests and procedures done to diagnose salivary gland cancer are used to help make decisions about treatment.

Sometimes childhood salivary gland cancer recurs (comes back) after treatment.

Treatment Option Overview

There are different types of treatment for children 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.

Because cancer in children is rare, taking part in a clinical trial should be considered. Some clinical trials are open only to patients who have not started treatment.

Children with salivary gland cancer should have their treatment planned by a team of doctors who are experts in treating childhood cancer.

Treatment will be overseen by a pediatric oncologist, a doctor who specializes in treating children with cancer. The pediatric oncologist works with other pediatric health professionals who are experts in treating children with cancer and who specialize in certain areas of medicine. This may include the following specialists and others:

• Pediatrician.
• Pediatric surgeon.
• Radiation oncologist.
• Pathologist.
• Pediatric ear, nose, and throat specialist.
• Pediatric nurse specialist.
• Social worker.
• Rehabilitation specialist.
• Psychologist.
• Child-life specialist.

Three types of standard treatment are used:

Surgery

Surgery to remove the tumor is the most common treatment for benign salivary gland tumors and malignant salivary gland cancer. If the parotid gland is removed during surgery, special care must be taken to avoid damage to the facial nerve.

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 area of the body with cancer.
• Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.

Radiation therapy may be given if the tumor is likely to spread.

Targeted therapy

Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells. Targeted therapies usually cause less harm to normal cells than chemotherapy or radiation therapy do.

There are different types of targeted therapies:

• Tyrosine kinase inhibitor (TKI) therapy blocks signals needed for cancer to grow. Entrectinib and larotrectinib are TKIs that may be used to treat salivary gland cancer with a certain gene change.

Targeted therapy is being studied for the treatment of childhood salivary gland cancer that has recurred (come back).

Treatment for childhood salivary gland cancer may cause side effects.

Side effects from cancer treatment that begin after treatment and continue for months or years are called late effects. Because late effects affect health and development, regular follow-up exams are important.

Late effects of cancer treatment may include the following:

• Physical problems that affect the following:
  • Dry mouth.
  • Trouble seeing.
  • Changes in the way the bones of the head and face grow.
  • Other changes in the child's appearance.
• Changes in mood, feelings, thinking, learning, or memory.
• Second cancers (new types of cancer).

Some late effects may be treated or controlled. It is important to talk with your child's doctors about the possible late effects caused by some treatments. 

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. Information about clinical trials supported by NCI can be found on NCI’s clinical trials search webpage. Clinical trials supported by other organizations can be found on the ClinicalTrials.gov website.

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 child's condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.

Treatment of Childhood Salivary Gland Cancer

Treatment of newly diagnosed salivary gland cancer in children may include the following:

• Surgery to remove the cancer. Internal or external radiation therapy may be given after surgery.

Treatment of Recurrent Childhood Salivary Gland Cancer

Treatment of recurrent salivary gland cancer in children may include the following:

• Targeted therapy (entrectinib or larotrectinib).
• A clinical trial that checks a sample of the patient's tumor for certain gene changes. The type of targeted therapy that will be given to the patient depends on the type of gene change.