Head & Neck

Salivary Gland Cancer

Salivary glands produce saliva to help you swallow, chew and digest food and to keep your mouth and throat moist. Saliva contains enzymes that begin the process of breaking down food and antibodies that help prevent mouth and throat infections.

Your head and neck contain major and minor salivary glands, with a set of three major glands on each side of your face. The largest are the parotid glands located just in front of each ear. The submandibular glands below your mandible (jawbone) are smaller. The sublingual glands under the mouth floor are the smallest. You also have hundreds of microscopic minor salivary glands throughout the lining of your lips and tongue as well as on the roof of your mouth and inside your cheeks, nose, paranasal sinuses, pharynx and larynx.

As the largest major salivary glands, the parotid glands are the site of most tumors. Although tumors aren’t common in minor salivary glands, they are more likely to be malignant when they do occur. Salivary gland cancers are sometimes found during routine dental visits or physical exams. Symptoms may include a lump in an ear, cheek, jaw, lip or inside the mouth; ear drainage; trouble swallowing; difficulty opening your mouth wide; facial numbness or weakness; or persistent facial pain.

Common Treatments

Your doctor will determine your treatment plan based on the type, stage and grade of your cancer. The grade indicates how abnormal the cells look under a microscope in comparison to healthy cells. Low-grade cancer tends to spread more slowly than high- grade cancer. Your overall health; the impact to your speech, chewing and swallowing; and your preferences are also considered. To ensure you feel informed, talk with your doctor about the benefits and risks as well as the potential side effects and late effects of each type of therapy before making decisions.

One or more of the following options, alone or in combination, or a clinical trial, may be part of your treatment plan. (See Treatment Options for general descriptions of each treatment type.)

Surgery

Surgery to remove the tumor and surrounding tissue is the most common treatment for salivary gland cancers. Most salivary gland cancers occur in the parotid glands and are often treated with one of the following procedures.

Superficial parotidectomy may be used to remove cancer in the outside part of the parotid gland, also known as the superficial lobe. This involves removing the lobe.

Total parotidectomy to remove the entire parotid gland may be used if the cancer extends to deeper tissues. Removal of the facial nerve may be required, which may affect facial movement.

Other surgical procedures include endoscopic surgery, removal of the submandibular or sublingual glands, and a lymph node dissection (lymphadenectomy) to remove lymph nodes.

More than one surgery may be needed to treat the cancer and to repair the area (see Reconstructive Surgery).

Radiation Therapy

Radiation therapy is most often used after surgery (adjuvant therapy) to kill remaining cancer cells, but it may be the main treatment if surgery is not an option. It is sometimes used to manage symptoms of pain, bleeding or trouble swallowing and in cases of recurrent or advanced salivary gland cancer. Radiation therapy may be given externally or internally. It may also be combined with chemotherapy (chemoradiation).

Immunotherapy

Immunotherapy in the form of immune checkpoint inhibitors may be used to treat recurrent or metastatic salivary gland cancer that has stopped responding to chemotherapy. Clinical trials may include other immunotherapy options.

Targeted Therapy

Tyrosine kinase inhibitors (TKIs) may be an option. These targeted therapy drugs are oral medications that detect and attack a neurotrophic tyrosine receptor kinase (NTRK) genetic fusion, a specific molecular (genetic) abnormality in a person’s tumor. This type of personalized treatment attacks the source of a tumor’s growth, focusing on certain parts of cells and the signals that cause them to grow unchecked or keep from dying. These signals are often sent by proteins called tyrosine kinases.

Other Treatment Options

Chemotherapy may be an approach used to treat late-stage cancer or to treat symptoms. Other treatments continue to be evaluated in clinical trials (see Clinical Trials).

Staging

Diagnosing your type of salivary gland cancer is an important step in creating the best treatment plan for you. Your doctor will perform a thorough exam, imaging studies, blood tests and a biopsy and use these test results to stage the cancer. Staging determines the extent of your cancer, where it is located and whether it has metastasized (spread) to nearby organs, tissues or lymph nodes, or to other parts of your body.

The TNM staging system, developed by the American Joint Committee on Cancer (AJCC), is typically used to classify and stage salivary gland cancer. This system classifies the cancer by tumor (T), node (N) and metastasis (M). The T category describes the size and location of the primary tumor. The N category indicates whether the lymph nodes show evidence of cancer cells. The number and location of these lymph nodes are important because they show how far the disease has spread. The M category describes metastasis (spread of cancer to another part of the body), if any.

Staging Criteria

Once the cancer is classified, an overall stage is assigned. Salivary gland cancer may be Stage 0 through Stage IV. Also known as “in situ,” Stage 0 is a precursor of an invasive cancer. Stages I and II are generally confined to the local area where the cancer is found, and Stage III has spread to the regional lymph nodes in the neck. Stage IV is further divided into Stages IVA, IVB and IVC. Stages IVA and IVB are locally or regionally advanced disease, and Stage IVC has spread to distant sites, such as the liver, lungs or bone.

These basic stages are designed to group patients who have a similar prognosis (outlook). This grouping allows doctors to more accurately predict outcomes for patients depending on the type of treatment they receive. In certain cancers, the stage is also determined by other factors.

Sometimes your doctor may reassess your stage after treatment or if cancer recurs. This is known as restaging. It is rarely done but typically involves the same diagnostic tests used for the original staging. If a new stage is assigned, it’s often preceded by an “r” to denote that it’s been restaged and different from the original stage given at diagnosis.

TNM Classification for Salivary Gland Cancer

Classification Definition
Tumor (T)
TX Primary tumor cannot be assessed.
T0 No evidence of primary tumor.
Tis Carcinoma in situ.
T1 Tumor 2 cm or smaller in greatest dimension without extraparenchymal extension (spread to surrounding tissues).
T2 Tumor larger than 2 cm but not larger than 4 cm in greatest dimension without extraparenchymal extension (spread to surrounding tissues).
T3 Tumor larger than 4 cm and/or tumor having extraparenchymal extension (spread to surrounding tissues).
T4 Moderately advanced or very advanced disease.
  T4a Moderately advanced disease.
Tumor invades skin, mandible (lower jaw), ear canal, and/or facial nerve.
  T4b Very advanced local disease.
Tumor invades skull base and/or pterygoid plates and/or encases carotid artery.
Node (N)
NX Regional lymph nodes cannot be assessed.
N0 No regional lymph node metastasis.
N1 Metastasis in a single ipsilateral (on the same side) lymph node, 3 cm or smaller in greatest dimension and ENE*(-).
N2 Metastasis in a single ipsilateral (on the same side) lymph node, 3 cm or smaller in greatest dimension and ENE*(+);
or larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(-);
or metastases in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(-);
or in bilateral (on both sides) or contralateral (on the opposite side) lymph node(s), none larger than 6 cm in greatest dimension, ENE(-).
  N2a Metastasis in single ipsilateral (on the same side) node 3 cm or smaller in greatest dimension and ENE*(+);
or a single ipsilateral node larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(-).
  N2b Metastases in multiple ipsilateral (on the same side) nodes, none larger than 6 cm in greatest dimension and ENE*(-).
  N2c Metastases in bilateral (on both sides) or contralateral (on the opposite side) lymph node(s), none larger than 6 cm in greatest dimension and ENE*(-).
N3 Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE*(-);
or metastasis in a single ipsilateral (on the same side) node larger than 3 cm in greatest dimension and ENE(+);
or multiple ipsilateral, contralateral (on the opposite side) or bilateral (on both sides) nodes, any with ENE(+);
or a single contralateral node of any size and ENE(+).
  N3a Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(-).
  N3b Metastasis in a single ipsilateral (on the same side) node larger than 3 cm in greatest dimension and ENE*(+);
or multiple ipsilateral, contralateral (on the opposite side) or bilateral (on both sides) nodes, any with ENE(+);
or a single contralateral node of any size and ENE(+).
Metastasis (M)
M0 No distant metastasis.
M1 Distant metastasis.
*Extranodal extension (ENE) refers to cancer cells that have spread beyond the lymph node into surrounding tissues.

Staging Salivary Gland Cancer

Stage T N M
0 Tis N0 M0
I T1 N0 M0
II T2 N0 M0
III T3
T0, T1, T2, T3
N0
N1
M0
M0
IVA T4a
T0, T1, T2, T3, T4a
N0, N1
N2
M0
M0
IVB Any T
T4b
N3
Any N
M0
M0
IVC Any T Any N M1

Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, Eighth Edition (2017) published by Springer Science+Business Media.

 

Key Takeaways

  • Salivary glands produce saliva to help you swallow, chew and digest food.
  • You have hundreds of salivary glands in the head and neck area.
  • Tumors most often occur in the parotid glands, which are the largest salivary glands.

Additional Resources

 

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