Salivary Gland Cancer

Salivary gland cancer is a rare disease that forms in the glands that produce saliva in your mouth and throat. Although uncommon, it requires specialized care and attention, as the type and location of the tumor significantly affects treatment and recovery.

Table of contents

• What is salivary gland cancer
• The salivary glands
• How common is this cancer
• Who is affected
• Causes and risk factors
• Symptoms and signs
• Diagnosis
• Treatment options
• Survival and prognosis
• Living with salivary gland cancer

What is salivary gland cancer

Salivary gland cancer is a rare disease in which malignant (cancer) cells form in the tissues of the salivary glands^[1]. 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^[4].

Not all tumors in the salivary glands are cancerous. More than half of all salivary gland tumors are benign, meaning they are not cancerous and do not spread to other tissues^[7]. Both benign and malignant tumors may affect any of your salivary glands^[1].

Salivary gland cancer is classified as a type of head and neck cancer^[4].

The salivary glands

• Parotid glands
• Submandibular glands
• Sublingual glands
• Minor salivary glands

There are three pairs of major salivary glands in your body. The parotid glands 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^[7].

The submandibular glands are found below the jawbone, while the sublingual glands are found under the tongue in the floor of the mouth^[4].

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, which is the roof of the mouth^[7]. Tumors rarely form in minor salivary glands, but most that do are malignant^[1].

How common is this cancer

Salivary gland cancer is rare. Only 1% of tumors affecting the head and neck are salivary cancer^[1]. Because this cancer is less common, survival statistics are harder to estimate than for other, more common cancers, and some statistics have to be based on a small number of people^[6].

The most common types of salivary gland cancer are mucoepidermoid carcinoma and adenoid cystic carcinoma. Together, they make up half of all malignant salivary gland tumors^[1].

Who is affected

Anyone can develop salivary gland cancer, but men are more likely to have malignant salivary gland tumors^[1]. Most salivary gland cancers occur in older people^[3].

You are more likely to develop cancer in a salivary gland if you are 55 or older^[1].

Causes and risk factors

The exact cause of most salivary gland cancers is unknown^[4]. However, several factors may increase the chance of getting this disease.

Being exposed to certain types of radiation may increase the risk of salivary gland cancer. This includes treatment with radiation therapy to the head and neck^[7].

You are also more likely to develop cancer in a salivary gland if you smoke or use alcohol frequently^[1].

Working in certain occupations may increase risk. These include plumbing, rubber products manufacturing, asbestos mining, and leatherwork^[1]. Being exposed to certain substances at work is considered a risk factor^[4].

Studies have shown that some rare types of salivary gland cancer may occur more commonly in people with certain viral infections, like Epstein-Barr virus and human papillomavirus (HPV). However, these infections do not cause salivary gland cancer. More research is needed to understand the connection^[1].

Symptoms and signs

A small number of people with salivary gland cancer do not have symptoms. In these cases, salivary gland cancer may be found during a regular dental check-up or physical exam^[7].

In most cases, salivary gland cancer causes a painless lump on a salivary gland. This is the most common symptom. A lump is usually painless and may appear in the area of the ear, cheek, jaw, lip, or inside the mouth^[7].

If you have a malignant salivary gland tumor, you are more likely to experience other symptoms, including weakness or numbness in your face, neck, jaw, or mouth^[1].

Other symptoms may include persistent pain in your face, neck, jaw, or mouth, difficulty opening your mouth fully or moving your facial muscles, trouble swallowing, and bleeding from your mouth^[1].

Additional signs include fluid draining from the ear^[4].

Diagnosis

Your healthcare provider diagnoses salivary gland cancer with a physical examination and a review of your medical and personal history. They will check for lumps in your salivary glands and surrounding areas^[1].

Tests that examine the head, neck, and the inside of the mouth are used to diagnose salivary gland cancer^[7].

The following procedures may be used. A physical exam and health history involves 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^[4].

MRI (magnetic resonance imaging) is a procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body^[4].

CT scan (CAT scan) is 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^[4].

Biopsy is a procedure to remove a sample of tissue for testing in a lab. To collect a sample of tissue, a fine-needle aspiration or a core needle biopsy may be used. During the biopsy, a thin needle is inserted into the salivary gland to draw out a sample of suspicious cells. The sample is sent to a lab for testing. Tests can show what types of cells are involved and whether the cells are cancerous^[9].

If you are diagnosed with salivary gland cancer, you may have other tests to see if the cancer has spread. These tests help your healthcare team find out the extent of your cancer, also called the stage. Cancer staging tests often involve imaging tests^[9].

Treatment options

The main treatments for salivary gland cancer are surgery, radiotherapy, and chemotherapy. You might have one or more of these treatments^[11].

Surgery is the most common treatment for salivary gland cancer. It works very well for early stage cancers^[11]. Surgery alone will cure some salivary gland cancers. For other cancers, a combination of surgery and radiotherapy will work better^[11].

The type of operation you have depends on the size of the cancer, where it is, and whether there is a risk that the cancer has spread to the lymph nodes around your salivary gland or in your neck^[11]. It can be harder to remove a cancer in the deeper parts of the salivary gland^[11].

During surgery, the doctor will examine the area around your cancer. They may remove some of the lymph nodes near the tumor. This is called a selective neck dissection. Your surgeon does this to help find out where the cancer is and to get rid of any remaining cancer cells. This reduces the risk of the cancer coming back in the lymph nodes^[11].

Radiotherapy uses high-energy rays to kill cancer cells. Your doctor may recommend that you have radiotherapy after surgery. This helps to kill any cancer cells that might have been left behind and reduces the risk of the cancer coming back^[11].

You might also have radiotherapy as the main treatment if it is not possible to remove your cancer in an operation. You may not be able to have surgery because the position of your tumor makes it difficult to reach, you have other illnesses or conditions and you cannot have a long anesthetic, or the cancer is advanced and cannot be completely removed^[11].

Chemotherapy uses anti-cancer drugs to disrupt and kill cancer cells. Chemotherapy does not work as well as surgery and radiotherapy for salivary gland cancer, so this is not a common treatment^[11].

You may have chemotherapy to treat advanced cancers or those that have spread to other parts of your body, if your cancer has come back after surgery and radiotherapy, or as part of a clinical trial^[11].

When salivary gland cancer spreads to other parts of the body, this is advanced cancer. Doctors might use chemotherapy to control more advanced cancers or as part of a clinical trial^[1].

Survival and prognosis

Survival depends on different factors, so no one can tell you exactly how long you will live^[17]. Your outcome depends on the stage of the cancer when it was diagnosed, meaning how big it is and whether it has spread. Survival is also affected by the site of the cancer^[17].

Certain factors affect your prognosis, which is your chance of recovery, and treatment options. These include the type of salivary gland cancer you have, whether the cancer has spread beyond your salivary glands, what the cells look like under a microscope, how the treatment will affect your speech, chewing and swallowing, and your general health and fitness^[1].

Your prognosis depends on various factors, including the salivary gland where the cancer starts and whether the cancer has spread beyond your salivary glands^[1].

Left untreated, pieces of tumors can break away and spread to other parts of your body through your bloodstream or lymphatic system. This process is called metastasis. Cancer that has metastasized is more challenging to treat than cancer that stays in your salivary gland. Salivary gland cancers can metastasize to your lungs, bone, and liver^[1].

Overall, for all people with salivary gland cancer in England, around 85 out of 100 people survive their cancer for 1 year or more, and around 65 out of 100 people survive their cancer for 5 years or more^[17].

Living with salivary gland cancer

The end of cancer treatment may bring mixed emotions. Even though treatment has ended, there may be other issues to deal with, such as coping with long-term side effects^[19].

Doctors may see you every month during the first year after treatment and every two months during the second year. During the third year after treatment, you may see your doctor every three months and then every six months to a year in the fourth and fifth years after treatment. During these appointments, your doctor may perform a physical exam, biopsies, and imaging tests to ensure the cancer has not returned^[21].

Sometimes surgery for parotid gland cancer may cause facial weakness and stiffness because a facial nerve was damaged or had to be sacrificed to remove the tumor. If the nerve is only bruised, these effects are usually temporary^[21].

Radiation can damage the salivary glands so they do not make enough saliva or the saliva they make is thick or sticky. Most people will have a dry mouth during radiation therapy, but it usually improves after radiation therapy is finished. It can take several months or years for dry mouth to improve. In some cases, it may be a permanent side effect of treatment^[19].

Having a dry mouth for a long time can cause problems with your teeth or gums. It is important that you see your dentist on a regular basis so that you can maintain your oral health^[19].

Frey syndrome is a long-term side effect of surgery to remove a parotid gland. It happens when nerves cut during surgery connect to the sweat glands in the skin while healing. Symptoms include flushing or sweating on one side of the face when eating. Most people do not find this a problem, but some people may have a lot of flushing and sweating that they find embarrassing^[19].

Speech and swallowing therapists can meet with you before treatment starts to explain how different therapies may affect your speech and swallowing abilities. Talking after surgery or radiation therapy may be difficult because of temporary tissue swelling in the mouth and throat. If any nerves are damaged during surgery, resulting muscle weakness may also affect speech and swallowing^[21].

Speech and swallowing therapy may be used throughout treatment to preserve as much function as possible. It may also be given afterward to help you regain or compensate for any lost function. Therapy usually consists of exercises to strengthen the muscles in the tongue, mouth, vocal cords, and throat^[21].

Salivary gland cancer and its treatments can affect your body image and your self-esteem. Often this is because cancer or cancer treatments may result in body changes such as scars, skin changes from radiation therapy, changes to the appearance of your face and neck, or drooping of your face or lip on one side. Some of these changes can be temporary, while others will last for a long time or be permanent^[19].