Salivary gland cancer is a rare disease in which malignant (cancer) cells develop in the tissue of the salivary gland. Exposure to certain types of radiation increases the risk of developing salivary cancer. The salivary glands produce saliva and release it into the mouth. Saliva contains enzymes that help in digesting foods and antibodies. Antibodies protect the mouth and throat from infections.
The most common signs and symptoms of salivary cancer include a lump or trouble swallowing. Tests that examine the head, neck and the inside of the mouth are used to diagnose the disease. Several factors affect the treatment options and prognosis (chance of recovery).
A small number of patients have no symptoms. In most cases, salivary gland cancer causes a painless lump on a salivary gland. If the salivary gland cancer is malignant, the patient may experience the following signs and symptoms:
- Difficulty swallowing
- Numbness in the part of the face
- Trouble opening the mouth fully
- Muscle weakness on one side of the face
- Persistent pain in the area of the salivary gland
- A lump or swelling on or near the jaw or in the neck or mouth
- Bleeding from the mouth
Salivary gland cancers are rare and their causes are not known. However, certain factors increase the risk of developing this disease. This may include:
- Older age
- Treatment with radiation therapy to the head and neck
- Exposure to certain substances at work
This disease can occur in any salivary gland located in or near the mouth. Most common tumors occur in the three major salivary glands which include the following:
- Parotid glands (inside each cheek)
- Submandibular glands (On the floor of the mouth)
- Sublingual glands (below the tongue)
The doctor diagnoses salivary gland cancer with a physical examination and a review of the patient’s medical history. Apart from this, the doctor advises certain tests to confirm the presence of the tumour. These may include the following:
- CT scan
- MRI scan
- Positron emission tomography (PET)
- Fine-needle biopsy
Once salivary gland cancer is diagnosed, the next step is to determine the stage or extent of the disease. Staging is important because it helps guide treatment decisions. The stages of salivary gland cancer are as follows:
- Stage 0: The cancer is in-situ and has not spread to the nearby lymph nodes.
- Stage I: The cancer is less than 2 cm in diameter and has not spread to the nearby lymph nodes or metastasized to distant organs.
- Stage II: The cancer is still in the salivary glands, but the size is between 2 cm to 4 cm in diameter.
- Stage III: The cancer has a diameter of more than 4 cm and has spread to the nearby soft tissue.
- Stage IV: The cancer has metastasized to the nearby lymph nodes and distant organs. This is the advanced stage.
Surgery is the main treatment option for benign salivary gland tumours. After surgery, the recovery focuses on preventing infection and managing pain. The doctor may prescribe drugs like antibiotics and pain medications to achieve the goal. For malignant salivary gland cancers, the doctor uses surgical procedures to remove the tumour. After surgery, the patient may require radiation therapy to the affected area by cancer and the draining lymph nodes.
Radiation kills all the cancer cells so cancer doesn’t return. When cancer spreads from the salivary glands to other tissues outside the head and neck, the doctor recommends chemotherapy.
- Surgery: The cancerous tumour and the surrounding affected tissue is removed surgically.
- Radiation therapy: Also known as radiotherapy, it involves the use of high-energy x-ray beams to kill the cancer cells as well as to shrink the tumours.
- Chemotherapy: The circulation of cytotoxic drugs throughout the patient’s bloodstream stops the cancer cells from rapidly dividing to prevent the spread of cancer.
- Targeted therapy: Certain drugs are used to target the specific genes and proteins that help cancer cells multiply in the body.
- Immunotherapy: Specific drugs are used to help the body’s immune system fight cancer itself.
Surgery is a preferred treatment for salivary gland cancer. The goal of surgery is to remove the tumour and any other cancerous mass. It is generally followed by chemo and radiation therapy to eliminate any residual or resurfacing cancerous cells and accelerate remission.
