Salivary Gland Cancer Treatment in Delhi, India

Salivary glands are a group of glands located in and around the oral cavity (mouth) and upper digestive tract. Their primary function is to produce saliva, a fluid that plays several important roles in digestion and oral health.

Saliva contains enzymes that help break down food, making it easier to swallow and digest. It also helps to lubricate the mouth, making it easier to speak and swallow. Apart from enzymes it also contains antibodies and proteins that protect the teeth and gums from bacteria, helping to prevent tooth decay and gum disease.

There are three pairs of major salivary glands:

• Parotid glands: These are the largest salivary glands and are located on each side of the face in front of the ears.
• Submandibular glands: These glands are located beneath the lower jawbone and produce saliva that drains into the mouth through ducts located under the tongue.
• Sublingual glands: These glands are located beneath the tongue and produce saliva that drains into the mouth through several small ducts.

In addition to these major salivary glands, there are also numerous minor salivary glands located throughout the lining of the mouth and throat.

Salivary gland cancer, also known as salivary gland tumour, is a condition characterised by the abnormal growth of cells within the salivary glands, and is relatively rare, constituting less than 1% of all cancers diagnosed annually. Despite its rarity, it can occur across all age groups and affect both men and women. The disease encompasses a diverse range of tumour types. These subtypes exhibit varying levels of aggressiveness, prognosis, and treatment modalities.

Salivary gland cancer encompasses various types of tumours, each classified based on the specific type of cells involved and their microscopic appearance. The main types of salivary gland cancer include:

• Mucoepidermoid Carcinoma: This is the most common type of salivary gland cancer, accounting for a significant proportion of cases. Mucoepidermoid carcinoma typically contains a mix of mucous-secreting cells, epidermoid (squamous) cells, and intermediate cells. These tumours can vary in their aggressiveness and may have different grades based on their histological features.
• Adenoid Cystic Carcinoma: Adenoid cystic carcinoma is characterised by slow, relentless growth and a tendency to invade nerves and blood vessels. Despite its slow-growing nature, it has a high propensity for local recurrence and distant metastasis, particularly to the lungs. Adenoid cystic carcinoma often presents as a painless mass and is notorious for its challenging management.
• Acinic Cell Carcinoma: Acinic cell carcinoma arises from cells that produce saliva (acinic cells) and usually presents as a slow-growing tumour. These tumours often occur in the parotid gland but can also arise in other salivary glands. While most acinic cell carcinomas are low-grade and have a favourable prognosis, some cases may exhibit more aggressive behaviour.
• Adenocarcinoma: Adenocarcinoma is a broad category of tumours that arise from glandular cells. In the context of salivary gland cancer, adenocarcinomas can manifest in various subtypes, each with distinct characteristics and clinical behaviour. Examples include papillary cystadenocarcinoma and polymorphous low-grade adenocarcinoma.
• Salivary Duct Carcinoma: Salivary duct carcinoma is a high-grade malignancy that resembles ductal carcinoma of the breast. These tumours typically arise in the parotid gland and may exhibit rapid growth and a propensity for local invasion and distant metastasis.
• Other Rare Subtypes: In addition to the aforementioned types, there are several rare subtypes of salivary gland cancer, such as clear cell carcinoma, oncocytic carcinoma, and carcinoma ex pleomorphic adenoma (malignant transformation of a benign pleomorphic adenoma).

In addition to these are also some common benign (non-cancerous) types of salivary gland tumours:

• Pleomorphic Adenoma (Benign Mixed Tumour): Pleomorphic adenoma is the most common benign tumour of the salivary glands. It typically arises in the parotid gland but can also occur in the submandibular and minor salivary glands. These tumours are usually slow-growing and well-defined, consisting of a mixture of epithelial and mesenchymal components.
• Warthin Tumour (Papillary Cystadenoma Lymphomatosum): Warthin tumour is the second most common benign salivary gland tumour, often occurring in the parotid gland. It is characterised by cystic spaces lined by epithelial cells and lymphoid tissue. Warthin tumours are typically slow-growing and rarely become malignant.
• Monomorphic Adenoma: Monomorphic adenomas are benign tumours composed of a single type of cell, usually ductal or myoepithelial cells. These tumours are typically well-circumscribed and may occur in any of the major or minor salivary glands.
• Basal Cell Adenoma: Basal cell adenomas are rare benign tumours that arise from basal cells of the salivary glands. They are typically slow-growing and may present as painless masses in the parotid gland or other salivary gland locations.
• Oncocytoma: Oncocytomas are benign tumours composed of oncocytes, which are large, eosinophilic cells with abundant mitochondria. These tumours are rare in the salivary glands but may occur in the parotid gland or other locations.
• Canalicular Adenoma: Canalicular adenomas are benign tumours that typically arise in the minor salivary glands of the oral cavity. They are characterised by a canalicular growth pattern and are usually slow-growing and asymptomatic.

Salivary gland cancer can develop due to a combination of genetic mutations and environmental factors. While the exact causes of salivary gland cancer remain unclear, several risk factors have been identified:

• Advanced Age: Salivary gland cancer is more commonly diagnosed in older adults, with the risk increasing with age.
• Radiation Exposure: Previous exposure to ionising radiation, whether for medical purposes (such as radiation therapy for head and neck cancers) or occupational exposure, increases the risk of developing salivary gland cancer.
• Prior Radiation Therapy: Individuals who have undergone radiation therapy to the head and neck region for previous cancers or other conditions may have an increased risk of developing salivary gland cancer later in life.
• Certain Genetic Syndromes: Inherited genetic syndromes, such as Lynch syndrome (hereditary nonpolyposis colorectal cancer) and Cowden syndrome, have been associated with an increased risk of salivary gland cancer.
• Exposure to Certain Substances: Prolonged exposure to certain substances or chemicals, such as asbestos, nickel refining, or rubber manufacturing, may elevate the risk of developing salivary gland cancer.
• Smoking and Tobacco Use: Although the link is not as strong as with other cancers, tobacco use, including smoking and smokeless tobacco products, has been implicated as a potential risk factor for salivary gland cancer.

Salivary gland cancer can present with various symptoms, which may vary depending on the size, location, and aggressiveness of the tumour. Some common signs and symptoms of salivary gland cancer include: 

• Painless Lump or Swelling: The most common early symptom of salivary gland cancer is a painless lump or swelling in the mouth, neck, or face. This lump may gradually increase in size over time.
• Difficulty Swallowing: As the tumour grows, it may obstruct the normal flow of saliva and interfere with swallowing, leading to dysphagia (difficulty swallowing) or a sensation of something stuck in the throat.
• Pain or Discomfort: In some cases, salivary gland cancer may cause pain or discomfort in the affected area, particularly if the tumour presses against nearby nerves or tissues.
• Facial Numbness or Weakness: Tumours located near facial nerves may cause facial numbness, weakness, or paralysis on one side of the face. This can manifest as drooping of the mouth or difficulty controlling facial expressions.
• Changes in Facial Appearance: As salivary gland tumours grow, they may cause visible changes in facial appearance, such as asymmetry or swelling on one side of the face.
• Difficulty Opening the Mouth: Some individuals with salivary gland cancer may experience difficulty opening their mouth fully, known as trismus, due to the presence of a tumour or inflammation in the affected area.

Diagnosing salivary gland cancer involves a two-pronged approach: a physical examination and various tests to confirm the presence and type of cancer. Here's a breakdown of the process:

• Medical History and Physical Examination: The doctor will begin by taking a detailed medical history, including any symptoms experienced and relevant risk factors. A thorough physical examination will be conducted to assess for signs such as lumps or swelling in the mouth, neck, or face, as well as any changes in facial nerve function.

• Imaging Studies:

• Ultrasound: Ultrasound imaging may be used to visualise the salivary glands and surrounding structures, helping to identify the location, size, and characteristics of any masses or tumours.
• CT (Computed Tomography) Scan: CT scans may be performed to obtain cross-sectional images of the head and neck region, providing additional information about the location and extent of the tumour.
• PET (Positron Emission Tomography) Scan: PET scans may be used to detect the presence of cancerous cells and assess whether the cancer has spread to other parts of the body (metastasis).
• Biopsy: A biopsy involves the removal of a small sample of tissue from the suspected tumour for microscopic examination by a pathologist. This is the most definitive method for diagnosing salivary gland cancer and determining its type and grade.

The diagnostic process for salivary gland cancer is comprehensive and typically involves collaboration among various healthcare professionals, including otolaryngologists, radiologists, pathologists, and oncologists.

The primary treatment modalities for salivary gland cancer may include:

• Surgery: Surgical removal of the tumour (resection) is often the mainstay of treatment for salivary gland cancer. Surgical options may include: 
• Superficial parotidectomy: Removal of the tumour while preserving surrounding healthy tissue, commonly performed for smaller tumours or those located in superficial areas of the parotid gland.
• Total Parotidectomy: Complete removal of the parotid gland, often necessary for tumours located deep within the gland or involving multiple areas.
• Submandibular Gland Excision: Surgical removal of the submandibular gland for tumours arising in this location.
• Neck Dissection: Removal of lymph nodes in the neck (cervical lymphadenectomy) may be performed if the cancer has spread to these nodes.
• Radiation Therapy: Radiation therapy uses high-energy beams to target and destroy cancer cells. It may be used alone or in combination with surgery. It is often employed after surgery to eliminate any remaining cancer cells and reduce the risk of recurrence.
• Chemotherapy: Chemotherapy involves the use of drugs to kill cancer cells or slow their growth. It may be used in cases where salivary gland cancer is advanced, has spread to other parts of the body, or is not amenable to surgery or radiation therapy. 
• Targeted Therapy: Targeted therapy drugs are designed to specifically target cancer cells by interfering with specific molecules or pathways involved in cancer growth and progression. These drugs may be used in cases where tumours have specific genetic mutations or are resistant to traditional treatments.
• Immunotherapy: Immunotherapy works by harnessing the body's immune system to recognize and destroy cancer cells. While not yet a standard treatment for salivary gland cancer, clinical trials are underway to evaluate the efficacy of immunotherapy in this disease.
• Supportive Care: Supportive care measures are aimed at managing symptoms and improving quality of life for individuals undergoing treatment for salivary gland cancer. This may include pain management, nutritional support, speech therapy, and psychological support.

Treatment decisions are made on a case-by-case basis, taking into account the individual's unique circumstances and preferences.

• Facial nerve damage: Tumours can grow near or press on facial nerves, causing weakness, paralysis, or involuntary twitching in one side of the face. This can affect smiling, blinking, and facial expressions.
• Difficulty swallowing : Large tumours or surgery can obstruct the swallowing mechanism, making it difficult to swallow food or liquids. This can lead to malnutrition and dehydration.
• Dry mouth: Treatment, particularly radiation therapy, can damage salivary glands, leading to reduced saliva production. This can cause dryness, discomfort, difficulty speaking, and increased risk of tooth decay.
• Speech problems: Facial nerve damage or swelling in the mouth or throat can affect your ability to speak clearly.
• Bleeding: Surgery or advanced tumours can lead to bleeding in the mouth or face.
• Infection: Following surgery, there's a risk of infection in the surgical site.
• Lymphedema: If lymph nodes are removed during surgery, it can lead to fluid buildup (lymphedema) in the face and neck, causing swelling and discomfort.
• Second cancers: Radiation therapy for salivary gland cancer can slightly increase the risk of developing another cancer in the treated area later in life.

Prevention strategies for salivary gland cancer primarily focus on reducing exposure to known risk factors and promoting overall health and well-being. Here are some key pointers for preventing salivary gland cancer:

• Protect Against Radiation Exposure: Minimise exposure to ionising radiation whenever possible, and ensure appropriate protective measures are in place during medical procedures involving radiation. Avoid unnecessary exposure to radiation sources in the workplace or environment.
• Maintain good oral hygiene: Regular brushing, flossing, and dental checkups can help keep your mouth healthy and potentially reduce the risk of infections that might be linked to salivary gland cancer.
• Limit tobacco use: Smoking and tobacco use are significant risk factors for many cancers, including some head and neck cancers. Quitting smoking or avoiding tobacco altogether can be highly beneficial for overall health and potentially reduce the risk of salivary gland cancer.
• Limit Exposure to Environmental Toxins: Minimise exposure to environmental toxins and carcinogens, such as asbestos, nickel, and certain industrial chemicals, which may increase the risk of developing cancer.
• Protect Against Viral Infections: Take preventive measures to reduce the risk of viral infections associated with salivary gland cancer, such as human papillomavirus (HPV) and Epstein-Barr virus (EBV). This may include practising safe sex and maintaining a healthy immune system.

How common is salivary gland cancer?

Salivary gland cancer is considered a rare type of cancer. It is still important to be aware of the symptoms and seek medical attention if you experience any concerns. Early detection is crucial for successful treatment, regardless of how common or uncommon the cancer may be.

What is the TNM staging system for salivary gland cancer?

The TNM staging system is widely used to classify the stage (severity) of salivary gland cancer. This system considers three key factors:

• T: Tumour size and spread to nearby tissues. (e.g., T1: small tumour confined to the gland, T4: large tumour invading surrounding structures)
• N: Involvement of lymph nodes. (e.g., N0: no lymph node involvement, N1: cancer spread to nearby lymph nodes)
• M: Distant metastasis (spread of cancer to other organs). (e.g., M0: no distant spread, M1: cancer has spread to distant organs)

Higher TNM stages generally indicate a more advanced cancer. 

How often should someone who has had salivary gland cancer undergo follow-up screenings?

Individuals who have had salivary gland cancer should undergo regular follow-up screenings as recommended by their doctor. Typically, follow-up appointments are scheduled every few months initially and then gradually spaced further apart over time. However, the frequency and duration of follow-up screenings may vary based on factors such as the type and stage of cancer, treatment received, and individual risk factors. It's important to adhere to the recommended follow-up schedule to monitor for any signs of recurrence or long-term effects of treatment.

Can salivary gland cancer affect the sense of taste?

Yes, salivary gland cancer and its treatment can affect the sense of taste, leading to alterations or loss of taste perception (dysgeusia). This can result from factors such as damage to the salivary glands, changes in saliva production, or side effects of radiation therapy or chemotherapy. These taste changes may manifest as a decreased ability to detect flavours, an altered taste sensation, or a persistent metallic or bitter taste in the mouth.

How to deal with changes in taste after radiation therapy?

To deal with changes in taste after radiation therapy, patients can try:

• Experimenting with different foods and flavours to find what is tolerable.
• Using seasonings and spices to enhance the taste of foods.
• Opting for foods with stronger flavours or textures.
• Maintaining good oral hygiene to keep the mouth clean and healthy.
• Consulting with a dietitian for personalised dietary recommendations.

What exercises can be done to improve swallowing after surgery?

Exercises to improve swallowing after surgery may include:

• Tongue exercises, such as tongue presses against the roof of the mouth.
• Swallowing exercises with various consistencies of food or liquids.
• Neck and throat stretching exercises.
• Chin tucks and head turns to strengthen swallowing muscles.

Are there any lifestyle changes that can reduce the risk of salivary gland cancer?

Yes, adopting a healthy lifestyle can help reduce the risk of salivary gland cancer. Lifestyle changes such as avoiding tobacco products, limiting alcohol consumption, maintaining a balanced diet rich in fruits and vegetables, practising good oral hygiene, and minimising exposure to environmental toxins may lower the risk of developing salivary gland cancer.

How does salivary gland cancer impact quality of life for patients and their caregivers?

Salivary gland cancer and its treatment can significantly impact the quality of life for patients and their caregivers. Patients may experience physical symptoms such as pain, difficulty swallowing, and changes in appearance or function, leading to emotional distress and psychological challenges. 

Caregivers may also face emotional and practical burdens, including managing the patient's care, supporting them through treatment, and coping with their own stress and anxiety.

Open communication, support networks, and access to counselling services can help address these challenges and improve overall well-being for patients and caregivers alike.

Are there any support groups available for salivary gland cancer patients?

Yes, there are support groups available for salivary gland cancer patients. These groups provide a supportive environment for individuals to share experiences, seek advice, and access resources. 

Some organisations offer online and in-person support groups for patients and caregivers. Additionally, many hospitals and cancer centres may have local support groups specifically for individuals affected by salivary gland cancer.

Reviewed By Dr Sowrabh Kumar Arora, Senior Director - Surgical Oncology (Head & Neck) On 18 July 2024.