Salivary gland cancer is a rare form of head and neck cancer that develops in the glands responsible for producing saliva. While these tumors can be benign, malignant forms require specialized diagnosis and treatment approaches that may include surgery, radiation therapy, and in some cases, participation in clinical trials.

Understanding Salivary Gland Cancer

Salivary gland cancer forms when malignant cells begin growing in the tissues of the glands that make saliva. Saliva, commonly known as spit, plays an essential role in digestion by helping to break down food. It also contains enzymes and antibodies that protect the mouth and throat from infections. These glands are located throughout the mouth and throat area, working constantly to keep your mouth moist and support healthy teeth.^[1]

The human body contains three pairs of major salivary glands. The largest are the parotid glands, which sit just in front of and slightly below each ear. Below the jawbone lie the submandibular glands, and under the tongue in the floor of the mouth are the sublingual glands. Most salivary gland tumors, both cancerous and noncancerous, begin in the parotid glands. In addition to these major glands, hundreds of tiny minor salivary glands line various parts of the mouth, nose, and voice box. Though tumors rarely form in these smaller glands, when they do, they are more likely to be malignant.^[4]

An important fact to understand is that more than half of all salivary gland tumors are benign, meaning they are not cancerous and do not spread to other tissues. However, when cancer does develop, it needs prompt attention because it can spread beyond the salivary glands to other parts of the body through the bloodstream or lymphatic system. When cancer spreads this way, doctors call it metastasis. The lungs, bones, and liver are common sites where salivary gland cancer may spread.^[1]

How Common Is This Cancer

Salivary gland cancer is considered quite rare. Only about one percent of all tumors affecting the head and neck region are salivary gland cancers. To put this in perspective, it affects roughly one in every 100,000 people in the United States. Because of its rarity, survival statistics can be harder to estimate compared to more common cancers, and some data must be based on smaller groups of patients.^[1][6]

Among the different types of salivary gland cancer, two forms are most frequently diagnosed: mucoepidermoid carcinoma and adenoid cystic carcinoma. Together, these two types account for about half of all malignant salivary gland tumors. The rare nature of this cancer means that many people may never have heard of it until they or someone they know receives a diagnosis.^[1]

Who Is Most Likely to Develop Salivary Gland Cancer

While anyone can develop salivary gland cancer, certain patterns have emerged from medical research. Men are more likely than women to develop malignant salivary gland tumors. Age also plays a significant role, with most cases occurring in people who are 55 years old or older. The risk increases as people age, making older adults the group most commonly affected.^[1]

Several lifestyle and environmental factors have been linked to an increased risk of developing this type of cancer. People who smoke tobacco or frequently consume alcohol face higher odds of developing salivary gland cancer. Past medical treatments can also raise risk levels. Individuals who have received radiation therapy to the head or neck area for other conditions may be at greater risk years after their treatment ends.^[1]

Certain occupations have been associated with higher rates of salivary gland cancer. Workers in specific industries, including plumbing, rubber products manufacturing, asbestos mining, and leatherwork, may face increased exposure to substances that could contribute to cancer development. While the exact mechanisms aren’t fully understood, workplace exposures to certain chemicals may play a role.^[1]

What Causes Salivary Gland Cancer

The exact cause of most salivary gland cancers remains unknown. Scientists have not identified a single factor that definitively causes cells in the salivary glands to become cancerous. This lack of a clear cause is common in many types of cancer, where multiple factors likely work together over time to trigger abnormal cell growth.^[7]

What researchers do know is that cancer begins when normal cells undergo changes in their genetic material. These changes cause cells to grow and multiply uncontrollably, forming tumors. In salivary gland cancer, these abnormal cells can develop in any of the salivary glands, though they most commonly appear in the three major gland pairs. The cancer may also arise in the hundreds of microscopic minor salivary glands scattered throughout the lining of the mouth, nose, and larynx.^[4]

When left untreated, these cancer cells don’t stay confined to their original location. Small pieces of the tumor can break away and travel through the bloodstream or lymphatic system to other organs. This spreading process, called metastasis, makes the cancer much more challenging to treat. Understanding where the cancer started and whether it has spread helps doctors determine the best treatment approach for each patient.^[1]

Recognizing the Symptoms

One of the challenging aspects of salivary gland cancer is that some people experience no symptoms at all, especially in the early stages. The cancer might only be discovered during a routine dental checkup or physical examination. However, when symptoms do appear, the most common sign is a painless lump in or near a salivary gland. This lump might be felt on the side of the face near the ear, in the cheek area, along the jaw, on the lip, or inside the mouth.^[7]

If the tumor is malignant rather than benign, additional symptoms are more likely to develop. These symptoms occur because the cancer affects nearby nerves and tissues. People may notice weakness or numbness on one side of their face, neck, jaw, or mouth. Some individuals experience persistent pain in these same areas that doesn’t go away with typical pain relief methods. The pain can become severe enough to interfere with sleep and daily activities.^[1]

As the tumor grows, it can interfere with normal functions. Difficulty opening the mouth fully or trouble moving facial muscles may develop. Some people find it hard to swallow food or liquids. In cases where the tumor is located near the ear canal, fluid may drain from the ear. Bleeding from the mouth can also occur. Any of these symptoms that persist should prompt a visit to a healthcare provider for evaluation.^[7]

Prevention Strategies

Because the exact causes of salivary gland cancer are not fully understood, prevention strategies focus on reducing known risk factors. The most important lifestyle change people can make is avoiding tobacco products entirely. Smoking has been linked to higher rates of salivary gland cancer, along with many other health problems. People who currently smoke should seek support to quit, and those who don’t smoke should never start.^[1]

Limiting alcohol consumption is another protective measure. Frequent or heavy drinking has been associated with increased cancer risk. Reducing alcohol intake to moderate levels or avoiding it altogether can help lower the chances of developing this and other types of cancer. These lifestyle modifications benefit overall health in numerous ways beyond cancer prevention.^[1]

For people who work in occupations with potential exposure to cancer-causing substances, following workplace safety guidelines is essential. Proper use of protective equipment and minimizing contact with hazardous materials can reduce risk. Workers in industries like rubber manufacturing, asbestos handling, or jobs involving chemical exposures should be particularly vigilant about safety protocols.^[1]

Regular dental and medical checkups play an important role in early detection. While these visits may not prevent cancer, they can help identify problems early when treatment is most likely to be successful. People who have received radiation therapy to the head or neck should discuss appropriate monitoring schedules with their healthcare providers, as they face higher risk and may benefit from more frequent examinations.^[7]

How the Body Changes with Salivary Gland Cancer

Understanding how salivary gland cancer affects the body helps patients and families know what to expect. The disease changes normal body functions in several ways. The salivary glands normally work continuously to produce saliva, which keeps the mouth moist, helps with chewing and swallowing, and protects teeth and gums from harmful bacteria. When cancer develops in these glands, their ability to function properly becomes compromised.^[4]

As a tumor grows within a salivary gland, it takes up space and puts pressure on surrounding tissues. This pressure can affect nearby nerves, which is why many patients experience numbness, weakness, or pain in the face. The facial nerve, which controls muscles throughout the face, runs very close to the parotid glands. When a tumor grows near this nerve, it can interfere with facial expressions and movement on that side of the face.^[1]

The cancer can also affect the body’s lymphatic system, which is part of the immune system. Lymph nodes near the salivary glands may become enlarged as they try to filter out cancer cells. When cancer cells break away from the main tumor and enter the lymphatic vessels, they can travel to lymph nodes in the neck and potentially to distant organs. This is why doctors carefully examine and sometimes remove lymph nodes during diagnosis and treatment.^[11]

The physical presence of a tumor can interfere with mechanical functions like opening the mouth, chewing, and swallowing. These activities require coordinated movement of multiple muscles and structures. A tumor pressing on these structures or causing swelling can make these everyday actions difficult or painful. This can affect a person’s ability to eat normally, speak clearly, and maintain good nutrition.^[13]