Salivary Gland Cancer

There are hundreds of minor salivary glands lining parts of the mouth and larynx and can be seen only though a microscope. Many of the salivary gland tumors are non cancerous and they do not spread to other tissues. Salivary gland cancer is a type of head and neck cancer. Advancing age, radiation therapy to head and neck and exposure to cancer-causing chemicals at work are largely factors that cause salivary gland cancer.

Causes and risk factors

Risk of getting salivary gland cancer increases as one gets older. Most develop it in their 50s and 60s. A person is at higher risk of developing salivary gland cancer if exposed to radiation. One may also come in contact with radioactive substances through work. In case of childhood cancer and treatment with radiotherapy, there is increased risk for at least 20 years post treatment. Skin cancer in the past also slightly increases the risk of cancer of salivary glands. Smoking tobacco tends to increase the risk. Human papilloma virus has been noticed in some types of salivary cancer and efforts are on to confirm this. Investigation into the low level radiation from mobile phones is also being done.

Signs and symptoms

While salivary gland cancer may not cause any symptoms, it is sometimes found during a regular dental check up. As symptoms caused by salivary gland cancer may also be caused by other conditions, consult a doctor if any of the following problems occur:

• A painless lump in the area of the ear, cheek, jaw, lip or inside the mouth
  
• Fluid draining from the ear
  
• Numbness in the face
  
• Weakness in the face
  
• Persistent pain in the face
  
• Trouble swallowing or opening the mouth wide.

Diagnosis

CT and MRI are used to determine if salivary gland cancer has spread to other tissues. An examination of the patient to check signs of health, in the neck, mouth and throat areas is vital. History of patient's health, habits and past illnesses and treatments is recorded. A small amount of glucose is injected into the vein and the PET (Positron Emission Tomography) scanner rotates around the body and takes images where glucose is used in the body. Malignant cells show up brighter in the picture because they are more active and take up more glucose than normal cells do. Endoscopy and biopsy are also done to test for salivary gland cancer. As salivary gland cancer is hard to diagnose, it is recommended to have tissue samples checked by a pathologist who has expertise in diagnosing salivary gland cancer.

Treating salivary gland cancer

Stage I is when cancer is confined to the salivary glands and is 2 cm or smaller; Stage II is larger than 2 cm but not larger than 4 cm; stage III is when it has spread to a lymph node or to soft tissues around the affected gland and stage IV has spread further.

There are three types of standard treatment used for salivary gland cancer – surgery, radiation therapy and chemotherapy. Some may receive more than one type of treatment. Therapy depends upon the stage the patient is in and the higher the stage, more the therapy and aggressive and multiple therapies are given.

Surgery

If the tumor is small and located in an easy-to-access spot, surgeon may remove it and a small portion of healthy tissue that surrounds it. Removing the entire salivary gland is done if the tumor is large and if the cancer extends to nearby structures such as facial nerves, ducts that connect to salivary glands, facial bones and skin may also be removed.

If the cancer has spread to lymph nodes in the neck, the surgeon may remove most of the lymph nodes. Reconstructive surgery is done by a plastic surgeon to improve the ability to chew, swallow, speak and breathe after the surgery. The patient may need grafts of skin, tissue or nerves from other parts of the body to rebuild areas in the mouth, throat and jaw.

Radiation therapy

Radiation therapy using neutrons which are more effective in treating certain salivary gland cancers is used. Post surgery, this therapy is used to kill cancer cells that might still remain. In case surgery is not possible and tumor is large and located in a place that makes removal too risky, radiation alone is used to treat salivary gland cancer.

Chemotherapy

Although this is not currently used as a standard treatment for salivary gland cancer, Chemotherapy is a drug treatment used to kill cancer cells. This may be an option for people with advanced salivary gland cancer that has spread to distant areas in the body.

Those who undergo radiation therapy to the head and neck often experience dry mouth which can be uncomfortable. This can lead to frequent infections in the mouth, cavities and pose problems in teeth and difficulty eating, swallowing and speaking. If such complications arise then:

• Brush teeth several times a day.
  
• Rinse mouth with warm salt water after each meal.
  
• Keep mouth moistened with water or sugarless candies.
  
• Choose moist food and moisten dry food with sauce, gravy, broth, butter or milk.
  
• Avoid acidic or spicy foods and drinks, such as caffeinated and alcoholic beverages.

Salivary gland

Salivary glands are exocrine glands producing saliva and amylase that helps break starch into maltose. Typical problems of salivary glands include obstruction and infection. When the saliva flow is obstructed due to stones or constriction, the salivary glands become swollen and painful. Furthermore, the accumulated saliva can get infected leading to increased pain and swelling. Mumps are a common infection of the salivary glands. Sometimes the salivary glands might show painless enlargement. This must be thoroughly investigated for malignancy. HIV and Sjogren's syndrome can cause an auto-immune condition where the salivary glands are infected. Diabetes can lead to enlarged salivary glands.

Sialadenitis

Sialadenitis is a condition of inflammation of the salivary gland, parotid or submandibular glands. There is pain, tenderness, swelling and redness of the salivary glands. Other symptoms of sialadenitis include fever, chills and pus. Chronic Sialadenitis is associated with recurrent inflammation of the salivary glands. Acute Sialadenitis is less common but can lead to infection and fever. MRI, CT and ultrasound are done to rule out any obstructions. Antistaphylococcal antibiotics are usually prescribed. Warm compress and oral hygiene are important.