Salivary Gland Cancer: Patient Guide

This page is for people facing a salivary gland tumor, and for the people helping them. It covers where these tumors start, the main subtypes, symptoms, staging, and treatment.

You have three pairs of major salivary glands. The parotid glands sit in front of and just below each ear. The submandibular glands sit below the jawbone. The sublingual glands sit under the tongue, in the floor of the mouth. Many small minor glands also sit in the lining of the mouth, throat, larynx (voice box), and sinuses.

Now the fact that shapes everything else. A lump is more likely to be cancer when it sits in a smaller gland. NCI gives the share of tumors that are malignant (cancer):

• Parotid: 20 to 25 percent of tumors are malignant
• Submandibular: 35 to 40 percent
• Palate, which holds minor glands: about 50 percent
• Sublingual: more than 90 percent

Most parotid lumps are benign (not cancer). A lump under the tongue is much more likely to be cancer, so have it checked.

These are uncommon cancers. The age-adjusted rate from 2018 to 2022 was 1.3 cases per 100,000 people a year. That is about 3 to 5 percent of all head and neck cancers.

Salivary glands produce an unusually long list of tumor types. Four account for most malignancies.

Mucoepidermoid carcinoma is the most common, at 29 to 34 percent of malignant tumors. It is graded on a point system. Zero to 4 points is low grade. Five to 6 is intermediate. Seven to 14 is high grade. That number belongs on your pathology report.

Adenoid cystic carcinoma makes up about 7.5 percent of epithelial malignancies. NCI calls it slow growing but aggressive. NCI says it has a remarkable capacity to come back. Ten-year survival is reported to be less than 50 percent.

Acinic cell carcinoma is about 17 percent of primary malignant salivary tumors. More than 80 percent of them start in the parotid.

Carcinoma ex pleomorphic adenoma accounts for 4.6 percent. It grows inside a tumor that used to be benign. That is one reason benign salivary tumors get removed rather than watched for years.

Two outliers frame the range. Squamous cell carcinoma of a salivary gland does badly. Survival is 24 percent at 5 years and 18 percent at 10 years. Polymorphous low-grade adenocarcinoma does remarkably well. Overall survival is 80 percent at 25 years.

The usual first sign is a lump, and NCI stresses that it is usually painless. It may sit near the ear, in the cheek, along the jaw, on the lip, or inside the mouth.

Other symptoms carry more weight. They suggest the tumor is doing more than sitting there:

• Fluid draining from the ear
• Trouble swallowing, or trouble opening the mouth wide
• Numbness or weakness in the face
• Face pain that does not go away

Facial weakness deserves its own line. The facial nerve runs directly through the parotid gland. NCI notes that nerve involvement affects the outlook, and that pain and facial paralysis are common in adenoid cystic carcinoma. Report a drooping eyelid or a lopsided smile right away. Do not wait for the next visit.

The list of known risk factors is short. Exposure to ionizing radiation is the main one. Four job exposures also appear: rubber products manufacturing, asbestos mining, plumbing, and some kinds of woodworking.

The workup starts with a physical exam and health history. Imaging follows, using MRI, CT, or PET. Endoscopy, a look inside with a thin lighted tube, is used at times.

Fine needle aspiration biopsy is the most common way to get tissue. A thin needle draws cells from the lump for examination. When that is not enough, an incisional biopsy takes a small piece. Sometimes the surgeon removes the tumor first and the pathologist examines it afterward.

For the major glands, the stages run this way:

• Stage 0: abnormal cells confined to gland ducts, called carcinoma in situ
• Stage I: tumor 2 cm or smaller, confined to the gland
• Stage II: tumor larger than 2 cm but not more than 4 cm, still confined
• Stage III: tumor larger than 4 cm, spread to soft tissue, or both. One lymph node may be involved
• Stage IV (A to C): progressively wider spread to skin, bone, nerves, lymph nodes, or distant organs. Your team can tell you which letter applies

Here NCI says something that surprises people. For adenoid cystic carcinoma, NCI says clinical stage may be a better predictor than histological grade (how abnormal the cells look under a microscope), and tumors larger than 4 cm had a worse course. Early-stage, low-grade tumors are usually cured by surgery alone.

Things NCI says affect the outlook include the gland involved, the histology, the grade, the stage, nerve involvement, and spread to lymph nodes or distant sites.

Perineural invasion means cancer traveling along nerves. NCI says it can occur, particularly in high-grade adenoid cystic carcinoma, and should be specifically identified and treated.

Surgery is the main treatment. NCI says early-stage, low-grade tumors are usually curable by adequate surgery alone.

Large bulky or high-grade tumors carry a poorer outlook. NCI says they may best be treated with surgery plus radiation afterward. Radiation may raise local control and survival when clear margins cannot be achieved. Clear margins mean no cancer is found at the edge of the removed tissue. That is often hard in an area crowded with nerves.

NCI says two radiation options have been effective for tumors that cannot be removed or that come back. One is fast neutron-beam radiation therapy. The other is an accelerated hyperfractionated photon-beam schedule. Ask your team whether either is an option for you. NCI also says tumors that cannot be removed, or that come back, may respond to chemotherapy.

• Which gland is involved, and what is the exact histologic subtype?
• What grade is it, and for mucoepidermoid carcinoma, what was the point score?
• Is the facial nerve involved, and can it be preserved?
• Was perineural invasion found, and were margins clear?
• Does my case call for radiation after surgery, and why?
• Is fast neutron therapy relevant here, and is there a center that offers it?
• Given adenoid cystic histology, how long will surveillance continue?

• National Cancer Institute — Salivary Gland Cancer Treatment (PDQ), Health Professional Version
• National Cancer Institute — Salivary Gland Cancer Treatment (PDQ), Patient Version