Oral Cancer and Salivary Gland Cancer in Children

Oral cancer refers to the formation of cancerous cells in the tissues of the mouth or oral cavity.

The cancer cells are commonly found in the following parts:

• Gingiva (gums)
• Front two-thirds of the tongue
• Buccal mucosa (the lining of the inside of the cheeks)
• Hard palate (the roof of the mouth)
• Floor (bottom) of the mouth under the tongue
• Retromolar trigone (the small area behind the wisdom teeth)

Most tumors originating in the oral cavity are benign. However, malignant tumors, such as lymphomas and sarcomas, are commonly found in children. Squamous cell carcinoma, which is the most common type of cancer in adults, is rarely found in children.

Salivary gland tumors are tumors originating from the salivary glands that make and release saliva into the mouth.

The three pairs of salivary glands include:

1. Parotid glands: Largest salivary glands located in front of and just below each ear. Most salivary gland tumors start from this gland. Each parotid gland's duct empties into the inside of the cheek and near the top back teeth.     
2. Submandibular glands: They are the second largest salivary glands and are located below the jawbone. They produce saliva that comes out under the tongue. A tumor that originates in this gland will appear toward the middle of the neck just under the jaw.
3. Sublingual glands: They are the smallest of all salivary glands and are located beneath the tongue on the floor of the mouth. Tumors rarely originate in this gland.

The most common benign salivary gland tumor found in the Parotid gland include:

• Pleomorphic adenoma
• Warthin’s tumor

Pleomorphic adenoma commonly grows in the submandibular gland and sublingual glands but does not grow in the parotid gland.

Consult your child’s doctor if your child shows the following symptoms as these could be signs of oral cancer:

• Lump or thickening in the oral cavity
• Unhealing sore in the mouth
• Bleeding, pain, or numbness in the mouth
• White or red patch on the gums, tongue, or lining of the mouth

Salivary gland tumors may exhibit several signs and symptoms in children, including:

• Pain in the mouth, cheek, jaw, ear, or neck that doesn’t heal
• A lump or swelling in the mouth, cheek, jaw, or neck
• Fluid draining from the ear
• Recent changes in size and/or shape of the left and right sides of the face or neck
• Weakness of the muscles on one side of the face
• Numbness in a part of the face
• Trouble opening the mouth widely
• Trouble swallowing

These signs could be caused by a benign tumor. Therefore, it is important to consult your child’s doctor to identify the cause.

A risk factor is something that increases your risk of cancer. Having a risk factor or multiple risk factors does not mean that you will get cancer. There are circumstances where people with multiple risk factors do not get cancer, and some people who get it may have few or no known risk factors. 

However, it is critical to be aware of the risk factors to avoid developing oral cancer.

Some of the risk factors in children include:

• HPV infection
• Poor oral health
• Gastroesophageal reflux disease
• Vitamin deficiencies
• Having chronic graft-versus-host disease
• Having certain genetic conditions, such as Fanconi anemia, dyskeratosis congenita, connexin gene mutations, epidermolysis bullosa, or xeroderma pigmentosum

Risk factors for childhood salivary gland cancer may include past chemotherapy or radiation treatment for leukemia, lymphoma, sarcoma, or other cancers.

Currently, there is no standard staging system for childhood oral cavity cancer. Various tests and procedures used to diagnose oral cavity cancer are useful in making treatment decisions.

The tests to identify oral and salivary gland cancer remain the same and usually include:

• Oral and physical examination: The physician assesses your mouth and body to check for any signs of illness or abnormalities. Your history, habits, and past illnesses and treatments will be noted to plan the treatment regimen.
• MRI: A procedure that uses a magnetic field, radio waves, and a computer to take detailed photos of specific areas of the body, such as the neck and head. This is also known as nuclear magnetic resonance imaging.
• PET/CT scan: Sometimes, a PET/CT or CT scan can be done simultaneously to increase the chances of identifying cancer.
• CT scan (CAT scan): This procedure takes detailed photos of the body from various angles and projects them in a series. A dye can be injected in a vein or swallowed to aid in better visualization of tissues and organs. Other names for CT scans are computed tomography, computerized tomography, or computerized axial tomography.
• Positron emission tomography (PET scan): This procedure detects malignant tumor cells within the body. A little amount of radioactive glucose (sugar) is injected into the vein. The PET scanner rotates around the body to take pictures of the areas where glucose has been used in the body. As malignant tumor cells are more active than normal cells and consume more glucose, they appear brighter in the image.
• Ultrasound exam: A procedure in which high-energy sound waves (ultrasounds) bounce off from the internal tissues and organs to create echoes. These echoes form a picture of the body commonly known as a sonogram.
• Biopsy: It involves the removal of cells or tissues to examine them under a microscope to check for signs of cancer.
• Fine needle aspiration biopsy: A procedure that uses a fine needle to remove tissue or fluid from a targeted spot.

Traditional treatment options for treating oral and salivary cancer may include:

• Surgery: Surgical removal of a benign or malignant tumor is the primary treatment option. Apart from removing the tumor, your physician may also remove the adjacent lymph node, in case cancer has spread to this region. 
• Radiation therapy: Radiation therapy uses high-energy rays to destroy cancerous cells.
  • Depending on the type of radiation given, there are two types of radiation therapy:
    • External beam radiation: The radiation comes from a machine kept outside the body.
    • Internal radiation: In this type, the doctor puts radioactive material inside the body.
  • Systemic treatments tend to destroy or kill tumor cells in the body completely. 
• Chemotherapy: Chemotherapy aims to kill or destroy cancer cells or prevent their differentiation. Chemotherapy can be either taken by an oral or intravenous route, and they enter the bloodstream to reach the cancer cells.

Newer treatment options for treating oral and salivary gland cancer include:

• Targeted cancer therapy: Targeted therapy aims to prevent the mutations that cause the cells to grow uncontrollably or directly attack the specific cancer cells. They are less harmful than chemotherapy or radiation therapy. Tyrosine kinase inhibitors therapy obstructs signals that aid the growth of cancer cells.

Cancer treatment can produce side effects that may start after treatment and continue for months and years. These effects are known as late effects and may include:

• Trouble seeing
• Dry mouth
• Significant changes in the child's appearance
• Changes in mood, feelings, thinking, learning, or memory
• Second cancers (new types of cancer)