The salivary glands are essential organs that produce saliva in the mouth, throat, and nose. Saliva plays a vital role in supporting the digestive process, protecting the teeth, and helping to prevent infections from entering the body through the mouth and nose.
Salivary gland tumours develop when a cell within a salivary gland undergoes a mutation, leading to rapid and uncontrolled growth and division.
Salivary gland cancer is considered rare. Many cases are diagnosed annually in India. The disease has a five-year survival rate of 76%, though this rate can vary depending on the specific subtype of salivary gland cancer.
Most salivary gland tumours are benign (non-cancerous). These do not spread to other parts of the body. While not cancer, they often require treatment because they can grow quite large, and a small number have the potential to become malignant over time.
Some tumours are malignant, or cancerous. These tumours have the ability to spread beyond their original site to nearby tissues, lymph nodes, and distant organs of the body.
Every person has hundreds of salivary glands, categorised into two main types:
Most saliva is produced by the three pairs of major salivary glands, where the majority of salivary gland tumours occur.
Hundreds of much smaller glands line the mouth, throat, and sinuses. They are too small to be seen without medical instruments. Minor salivary gland tumours are rare but are more likely to be cancerous than those in the major glands. Many minor salivary gland cancers begin in the roof of the mouth.
There are over 20 types of malignant salivary gland tumours, and treatment plans often differ based on the specific type. The most common types include:
This is the most frequently occurring type of salivary gland cancer. Tumours are categorised as low-grade, intermediate-grade, or high-grade, with lower-grade tumours generally being less aggressive.
This is the most common tumour of the minor salivary glands and the second most common in the major salivary glands. It has a tendency to spread along nerves, particularly the facial and trigeminal nerves.
A common salivary gland cancer known for its tendency to recur at the site of its original location.
A risk factor increases an individual's likelihood of developing a specific disease. Risk factors for salivary gland cancer include:
The majority of salivary gland cancer cases are diagnosed in individuals aged 55 or older.
Patients who have received radiation treatment to the head and neck for another cancer have a higher risk. However, the benefits of radiation therapy significantly outweigh this risk.
Smoking is a known risk factor for some benign salivary gland tumours, and doctors are continuing to study its link to malignant salivary gland cancer.
Exposure to specific chemicals in certain industries, such as plumbing, carpentry, and manufacturing rubber products, increases the risk of some rare subtypes of salivary gland cancer.
Human papillomavirus (HPV) is a cause of several cancers (e.g., throat and cervical cancer). There is limited evidence to suggest that HPV may also be a risk factor for salivary gland cancer, a connection doctors are currently investigating.
Salivary gland cancer symptoms vary depending on the tumour's location but typically appear in the head and neck area, making them relatively easy to notice. As a result, the disease is often diagnosed in its early stages.
Common symptoms of salivary gland cancer include:
A usually painless lump in the ear, cheek, jaw, lip, neck, or mouth. This is the most common symptom, though pain may develop as the cancer grows and presses on surrounding areas.
Difficulty opening the mouth widely.
Weakness on one side of the face, which may worsen over time.
Persistent pain or numbness in the face.
Swelling of the face or neck, which can cause an asymmetric appearance.
It is important to note that most people with these symptoms do not have salivary gland cancer. However, any persistent signs or symptoms should be discussed with a doctor, as they may indicate other health problems.
An accurate diagnosis is the essential first step toward successful treatment for salivary gland cancer. At SSCHRC, we have pathologists who specialise in diagnosing head and neck cancers, including rare conditions like salivary gland cancer.
If salivary gland cancer is suspected, your doctor will review your medical history and overall health. You will then undergo tests to determine the specific type and stage (extent) of the cancer. These tests are also used to monitor the disease and its response to treatment.
A biopsy is the only way to conclusively confirm a diagnosis of salivary gland cancer. During a biopsy, doctors remove a sample of the suspected cancerous tissue for examination under a microscope. The method used depends on the tumour's location. Common biopsy methods include:
Imaging examinations are crucial for locating the suspected cancer, checking for spread, assisting in surgical planning, determining the cancer's stage, and monitoring the disease and its response to treatment.
Imaging exams for salivary gland cancer may include:
CT or CAT (Computed Axial Tomography) scans
PET (Positron Emission Tomography) scans
MRI (Magnetic Resonance Imaging) scans
Ultrasound
Chest and dental X-rays
Once a diagnosis is confirmed, your doctor will determine the cancer's stage, which classifies how far the disease has spread. Staging is vital for planning the most effective treatment. Staging is based on the system from the National Cancer Institute.
(Carcinoma in Situ): Abnormal cells are found only in the lining of the salivary ducts or the small sacs of the gland. These abnormal cells may potentially develop into cancer and spread.
Cancer has formed and is confined to the salivary gland, measuring 2 centimetres or smaller.
The tumour is in the salivary gland only and is larger than 2 centimetres but not larger than 4 centimetres.
The tumour is larger than 4 centimetres, and/or the cancer has spread to soft tissue surrounding the salivary gland; OR the tumour is any size and may have spread to soft tissue around the gland. Cancer has spread to one lymph node on the same side of the head or neck as the tumour. This lymph node is 3 centimetres or smaller, and the cancer has not grown outside the lymph node.
Stage IVA: Cancer has spread to the skin, jawbone, ear canal, and/or facial nerve. Cancer may have spread to a lymph node (up to 3 cm, not spread outside) on the same side; OR the tumour is any size and may have spread to surrounding soft tissue or structures (skin, jawbone, etc.), with specific patterns of spread to lymph nodes.
Stage IVB: Involves more extensive lymph node spread OR cancer has spread to the bottom of the skull and/or surrounds the carotid artery, regardless of lymph node status.
Stage IVC: Cancer has spread to distant parts of the body, such as the lungs.
Salivary gland cancer treatment plans are highly individualised and can change significantly based on the tumour's exact location and subtype. Even minor variations can be crucial. The right, tailored plan can greatly reduce the chance of the cancer returning and help maintain your quality of life, including your ability to speak, swallow, and hear.
At SSCHRC, patients receive care from a dedicated team of salivary gland cancer experts, including a surgeon, a radiation oncologist, and a medical oncologist. All specialists are highly experienced in treating this rare cancer. They collaborate closely to discuss each case and develop a personalised treatment plan.
Treatment options may involve advanced and cutting-edge interventions, such as targeted therapy, and advanced robotic surgical techniques.
Surgery is the primary treatment for most salivary gland cancers. Most procedures require incisions in the skin to reach the tumour. Depending on the tumour's location, some can be performed using an endoscope—a thin, flexible tube inserted through the mouth, with tools at its end to remove the tumour.
The type of parotid surgery depends on whether the tumour is confined to the superficial lobe or has spread to the deep lobe:
A key goal in all parotid gland surgeries is to remove the tumour while preserving the function of the facial nerve, which controls facial movement and runs through the gland.
Surgery for these glands typically involves removing the entire gland and possibly nearby tissue. Nerves controlling the tongue, parts of the face, and taste may also be affected.
The surgical approach for this cancer depends on the tumour's precise location. A small margin of healthy tissue surrounding the tumour may be removed during the procedure.
Most salivary gland surgery does not require complex reconstruction. In rare instances where surgery impacts the patient's appearance or ability to chew and swallow, these issues are addressed in the care plan. Reconstructive surgery is usually performed at the same time as the tumour removal surgery.
Radiation therapy uses potent, focused beams of electromagnetic energy to kill cancer cells. Doctors employ various techniques to accurately target the tumour while minimising damage to surrounding healthy tissue.
For salivary gland cancer, radiation therapy is typically used after surgery to eliminate any remaining cancer cells. It is also an option when surgery is not possible.
Types of radiation used include:
Chemotherapy drugs are used to kill cancer cells, control their growth, or ease disease-related symptoms. Treatment may involve a single drug or a combination, depending on the cancer type and its growth rate. Chemotherapy is not frequently used for salivary gland cancer but may be used in combination with radiation therapy in selected cases. It can also be an option for patients with Stage IV cancer.
Targeted therapy drugs are specifically designed to stop or slow the growth or spread of cancer at a cellular level. Cancer cells depend on specific molecules (often proteins) to survive, multiply, and spread. Targeted therapies are designed to interfere with, or target, these molecules or the cancer-causing genes that produce them.
This is a type of immunotherapy. Immune checkpoint inhibitors work by preventing the body's immune system from 'turning off' before the cancer has been completely eliminated. These inhibitors are only used in select cases.
Salivary gland cancer and its treatments can affect a person's ability to eat, drink, and speak, as well as their appearance. SSCHRC offers a range of therapies and services to help patients adjust to and overcome these challenges.
Follow-up Care: Regular follow-up and screenings are crucial due to the high risk of salivary gland cancer recurrence. Patients are advised to see their doctors every three to six months for the first two years after treatment, as most recurrences occur within this timeframe. Patients are also strongly urged to avoid smoking and drinking alcohol during and after treatment, as these habits can reduce treatment effectiveness, worsen side effects, and significantly increase the chance of the cancer returning.