Oral Cavity Cancer (Tongue and Mouth)

Oral Cavity Cancer (Tongue and Mouth) Overview

Oral cavity cancer (also called oral cancer or cancer of the mouth) develops when a tumor forms in the oral cavity, which includes the following structures:

• Front two-thirds of the tongue
• Roof or floor of the mouth
• Gums
• Lips
• Lining of the cheeks and/or lips

These tumors arise when cells inside the oral cavity mutate abnormally in a process called oncogenesis. Nearly all oral cancers are squamous cell carcinomas—also known as squamous cell cancers. These cancer cells are thin and flat and form in the lining of the mouth. Oral cavity cancer is a type of head and neck cancer. It is a life-threatening and life-altering disease that often necessitates a “new normal” for patients who are diagnosed. Cancer within the mouth can spread rapidly and, as with other cancers, early detection improves the effects of treatment. If caught quickly, oral cancer responds well to treatment. Cancer of the mouth accounts for about 3% of all cancers diagnosed annually, or approximately 54,000 cases per year. Oral cancer can be diagnosed by a physician or dentist. Many dentists screen for oral cancer of the tongue or mouth during an annual dental exam by examining your mouth, tongue, lips, and neck.

Anatomy of the Oral Cavity

Your oral cavity is comprised of your mouth, including the following:

1. Tongue (front two-thirds)
2. Teeth
3. Gums
4. Roof of your mouth (hard palate)
5. Floor of your mouth (under your tongue)
6. Buccal mucosa (cheek and lip lining)
7. Retromolar trigone (the small area of tissue behind your wisdom teeth)

Oral Cavity Cancer Treatments

Oral cancer can be treated by surgery, radiation therapy, and/or chemotherapy. Most often, cancer of the mouth is treated with a combination of these treatments. For most oral cavity cancers, a patient will undergo surgery first, followed by radiation and/or chemotherapy, depending on a tumor’s characteristics. Treatment is based on the size and type of the tumor, where the oral cancer of the tongue or mouth originated, and whether the cancer has metastasized. Patients with oral cavity cancer are often treated by head and neck surgeons; ear, nose, and throat doctors; oncologists; and radiation oncologists.

Surgery

Surgery is usually the first line of treatment for oral cancer. The best chance for a good outcome, and/or a complete cure, is when all of the following are true:

• You are healthy enough to undergo surgery
• The surgery is performed within 30 days of diagnosis
• The cancer can be fully removed

The scope of surgical intervention is dependent upon the size, location, and spread of the cancer. Surgery for oral cancer can be complex. Treatment involves removing the tumor, along with a cuff of normal tissue (called the margin) to maximize the likelihood that all cancer is removed. Lymph nodes that may be at risk of developing metastatic growths are also removed in an operation called a neck dissection. Types of oral cavity cancer surgery include:

• Glossectomy to remove a part of, or all of, the tongue
• Laryngectomy to remove all of, or a portion of, your voice box (larynx)
• Oral cavity composite resection, where a portion of the jaw is removed with other soft tissues of the oral cavity like the tongue or floor of mouth

The next phase of surgery involves reconstructive surgery to help restore form and function of the mouth and surrounding structures. The primary purpose of reconstructive surgery is to prevent saliva leakage by assembling structures of the oral cavity in a way where saliva remains in the mouth. The secondary focus is to restore function. As the anatomy of the head and neck are critical to a person’s ability to breathe, speak, and swallow, reconstruction to help restore these functions is critical. For example, the tip of your tongue is important for speech as it interacts with your teeth, mouth, and lips to create sound and form words. If a tumor on the tongue is removed, surgeons will try to spare as much of the tongue as possible so patients can speak and swallow. The final goal of head and neck reconstruction is to restore these functions and attempt to optimize cosmesis, to preserve and restore one’s outward physical appearance.

After surgery, radiation therapy or chemotherapy—or a combination of the two—is often the next step for patients whose tumor has aggressive features on final analysis. All tumors are reviewed after surgery by a pathologist, who examines the tissue under a microscope to determine the overall size of the tumor, margin status, number of lymph nodes involved, and presence of aggressive features like:

• Perineural invasion (tumor crawling along nerves)
• Lymphovascular invasion (tumor growing into lymphatic channels or blood vessels)
• Extra nodal extension (whether tumor in any lymph nodes has broken through the lymphnode capsule)

This final pathology report determines the stage of the tumor and whether radiation therapy or chemotherapy will be beneficial. 

Radiation Therapy

Radiation therapy describes the use of radiation – or beams of intensely focused, high-energy X-rays, gamma rays, electron beams, or protons – to destroy the cancer cells and treat cancers of the mouth. One of the most common forms of cancer treatment, radiation is generally administered through external beam radiation therapy (EBRT) or intensity modulated radiation therapy (IMRT). Radiation therapy does not physically remove a tumor or lesion. Rather, it damages the DNA of a tumor’s cells, thereby reducing or eliminating its ability to continue growing.

Chemotherapy

Chemotherapy is the use of medicine to treat cancer and prevent tumor growth by destroying rapidly reproducing cancer cells in your body. It can be administered by infusion, injection, or by mouth. It is often used if a cancer has metastasized, or spread. Chemotherapy is also used to lessen the likelihood that cancer will return, and it can also ease cancer symptoms by reducing the stress tumors place on nearby structures and organs.

It is a treatment often used in combination with other therapies, including radiation and surgery. While chemotherapy has proven to be an effective treatment for cancer, it can also destroy healthy cells, creating side effects that can seriously impact your quality of life.