This page was reviewed under our medical and editorial policy by
Beomjune B. Kim, DMD, MD, FACS, Head and Neck and Microvascular Reconstructive Surgeon
This page was reviewed on June 14, 2023.
Grouped as a type of head and neck cancer, mouth cancer (or oral cancer) may develop in the following areas:
According to the American Society of Clinical Oncology (ASCO), the majority of oral cancers, more than 90 percent, are squamous cell carcinomas that begin in the flat squamous cells lining the throat and mouth.
Mouth cancer is rare. As a frame of reference, below are U,S. Centers for Disease Control and Prevention numbers for U.S. oral cancer cases diagnosed in various parts of the mouth in 2016.
Gum cancer occurs when cells in your gum tissue grow out of control, forming malignant lesions and/or tumors. It’s a rare, slow-growing carcinoma, accounting for 6 percent of oral cancers, according to the European Journal of Dentistry. Because of similar symptoms, gum cancer can be easily mistaken for gingivitis.
Symptoms of gum cancer may include:
Inner cheek cancer is typically a squamous cell carcinoma, meaning it most often develops in the squamous cells that make up the tissue lining the cheeks. Compared with other oral cancers, buccal mucosa squamous cell carcinoma is considered to be aggressive with rapid growth, deep penetrations and a high rate of recurrence.
Signs of buccal mucosa cancer may include:
Floor of the mouth cancer occurs when cancer cells form in the tissue under the tongue. This type of cancer often appears as a mouth ulcer that doesn’t heal, and it may be confused with a canker sore.
Other signs of floor of the mouth cancer may include:
Roof of mouth cancer forms in the bony structures of the hard palate. Because of its proximity, this cancer may spread to the nasal cavity when it reaches an advanced stage. Hard palate cancer is typically seen or felt by the naked eye, most often beginning with a painful sore on the roof of the mouth that doesn’t heal.
Other signs of hard palate cancer may include:
There is no single known cause for mouth cancer. Rather, a combination of environmental and lifestyle factors, as well as genetics, may contribute to its development.
However, several risk factors are known to increase the risk of developing oral cavity cancers, including:
Tobacco and alcohol use: Smoking or chewing tobacco is one of the main risk factors for developing oral cavity cancers. Likewise, heavy drinking increases the risk of mouth cancer. Combined, smoking and drinking can increase your risk of developing cancers of the mouth by 30 times, according to the American Cancer Society (ACS), as compared with people who don’t smoke or drink. Moreover, according to ASCO, 85 percent of head and neck cancers are linked to tobacco use.
Betel quid: Made from betel nut, betel quid is a popular product in certain areas of the world, such as Southeast Asia and South Asia. Those who chew betel quid are more likely to develop mouth cancer.
Human papillomavirus (HPV) infection: HPV infection is associated with a small number of oral cavity cancers; it’s much more likely to cause oropharyngeal cancers (carcinomas of the tonsils, throat and base of the tongue).
Gender: Oral cavity cancer occurs twice as frequently in men than in women, according to the ACS, possibly due to alcohol and tobacco use.
Age: Young people are far less likely to have oral cavity cancers because these take many years to develop. Most often, these cancers occur in people older than age 55, according to the ACS.
Ultraviolet (UV) light exposure: Too much UV light exposure from the sun is linked to an increased incidence of lip cancers.
Suboptimal nutrition: A diet low in fruits and vegetables is associated with an increased risk of mouth cancers.
Genetic syndromes: People born with the inherited genetic syndromes Fanconi anemia and dyskeratosis congenita have an increased risk of developing mouth cancers.
Treatment of oral cavity cancers depends on your overall health along with your cancer’s:
In addition to treating the cancer, options also aim to preserve the function of the structures surrounding the cancer so that your quality of life is not drastically altered.
Common mouth cancer treatments may include:
Surgery: The goal of surgery is to completely remove the tumor and have negative margins, meaning there is no visible cancer left in healthy surrounding tissues. Removal of a tumor in this area of the body means you may also need reconstructive surgery. Sometimes, surgery is followed by radiation and/or chemotherapy or other therapies. Depending on the location, stage and extent of the cancer, patients may require more than one surgery.
Radiation therapy: Radiation therapy uses high-energy X-rays or other particles to kill cancer cells. With external beam radiation therapy (EBRT),a machine targets the tumor from outside the body. For recurrent cancer, doctors may recommend brachytherapy (internal radiation therapy), which involves the insertion of tiny radioactive rods or pellets inside of or near the area where the cancer is growing.
Chemotherapy: This type of treatment works by destroying cancerous cells systemically throughout the body. Chemotherapy is often used in combination with radiation therapy, called chemoradiation.
Targeted drug therapy: This drug treatment targets specific cancer genes, specific cancer proteins, or the tissue environment that allows cancer to grow, which helps limit the damage to healthy cells. Targeted drugs may be used in conjunction with chemotherapy and/or radiation.
Immunotherapy: These drugs are designed to increase your body’s natural defenses against cancer by improving or restoring the function of your immune system. They do this by helping your immune system to recognize and destroy cancer cells. Keytruda (pembrolizumab) and Opdivo (nivolumab) are two approved immunotherapy drugs used in the treatment of squamous cell carcinomas of the head and neck that have spread or recurred.
Survival rates can provide a better understanding of your treatment options, but they cannot predict how long you’ll live. Below are the current five-year relative survival rates for floor of the mouth cancers, as well as overall mouth cancers:
Floor of the mouth: According to the ACS, the five-year relative survival rates for floor of the mouth cancer are:
Cancers of the gum and other parts of the mouth: Survival rates by stage are not available, but the overall five-year relative survival rate for people with oral or oropharyngeal cancer is 66 percent, according to ASCO. If caught and diagnosed early, that five-year relative survival rate jumps to 85 percent. Regional spread has a five-year relative survival rate of 67 percent, and distant spread has a five-year relative survival rate of 40 percent.
It’s important to keep in mind that these are estimates based on years of past data and treatments. Improved diagnosis and treatments will have a positive impact on these estimates, and possibly you and your journey.