Oral cancer (also known as oral cavity cancer or mouth cancer) develops in the tissues of the mouth or the throat. It belongs to a larger group of cancers called neck and head cancers. It mostly develops in the squamous cells found in the tongue, mouth, and lips. Most often it comes under the category of oral and oropharyngeal cancer. The latter affects the back of the mouth and lining of the throat.
Oral cancers are most often found after they have spread to the lymph nodes of the neck. Early detection and treatment is the key to surviving oral cancer.
Oral cancer ranks in the top three of all cancers in India, which accounts for more than 30% of all cancers reported in the country. Having said that, oral cancer control is rapidly becoming a global health priority worldwide.
Types of oral cancer
A majority of mouth cancers are squamous cell carcinoma. It is true regardless of where in the mouth the cancer starts:
- Squamous cell carcinoma of the oral cavity – Squamous cells are flat, thin cells that look like fish scales. These are found in the tissue that forms the surface of the skin, the lining of the respiratory and digestive tracts, and the lining of the hollow organs of the body.
Squamous cell carcinoma mostly appears on parts of the body frequently exposed to the sun, such as ears, face, and neck. But it can also arise in the mouth.
Less common cancers of the oral cavity include:
- Oral Verrucous Carcinoma – It is a rare subtype of squamous cell carcinoma. This low-grade cancer rarely metastasizes (spreads to various sites). It comprises less than 5% of all diagnosed oral cancers, and can spread deeply into the surrounding tissue, requiring surgical removal with a wide margin of the surrounding tissue.
- Oral Melanoma – Melanoma forms in the pigment-producing cells that give skin its color. Melanoma of the neck and head can start anywhere on the skin or inside the oral or nose cavity.
The most common symptoms of oral cancer are:
- Development of velvety red, white, or speckled (white and red) patches in the mouth
- Unexplained bleeding in the mouth
- Persistent sores on the neck, face, or mouth that bleed easily and do not heal within two weeks
- Thickening/ swelling, bumps or lumps, crusts/ rough spots or eroded areas on the gums, lips or other areas inside the mouth
- Unexplained loss of feeling, numbness, or pain/tenderness in any area of the mouth, face, neck, or ear
- A soreness that something is caught in the back of the throat
- Difficulty in speaking, chewing or swallowing or moving the tongue or jaw
- Chronic sore throat, hoarseness or a change in voice, especially slurred speech
- A change in the way your teeth fit together
- A lump in the neck
In case you notice any of these changes, you should contact a doctor immediately for a test.
Causes and diagnosis
The main causes of oral cancer include:
- Tobacco and alcohol use – Tobacco use of any kind, including cigarette smoking, puts you at a high risk for developing oral cancers. Heavy alcohol use also increases the risk. Using alcohol and tobacco together increases the risk even further.
- Risk increases with age – Oral cancers mostly occur in people over the age 40.
- HPV – Infection with the sexually transmitted human papillomavirus, especially the HPV 16 type, has been linked to oral cancers.
- Sun Exposure – Cancer of the lip can be caused by high sun exposure.
Because oral cancer can spread quickly, early detection is utmost important. An oral cancer exam can detect early signs of cancer. It is usually painless and takes only a few minutes. Many dentists will perform the test during the regular dental check-up. During the exam, the dentist or dental hygienist will check your face, lips, neck, and the entire mouth for possible signs of cancer.
Stages and treatment options
There are four stages of oral cancer:
- Stage 1 – The tumor is 2 centimeters (cm) or smaller and the cancer has not spread to the lymph nodes.
- Stage 2 – The tumor is between 2-4 cm and cancer cells have not spread to the lymph nodes.
- Stage 3 – The tumor is either larger than 4 cm and has not spread to the lymph nodes; or is any size and has spread to one lymph node but not to the other parts of the body.
- Stage 4 – Tumors are any size and the cancer cells have spread to the lymph nodes, nearby tissues, or other parts of the body.
Treatment for oral cancer will vary depending on the type, stage, and location of cancer at the time of diagnosis:
- Surgery – Treatment for early stages usually involves surgery to remove the cancerous lymph nodes and tumor. Additionally, other tissues around the neck and mouth may be taken out.
- Radiation therapy – This involves a doctor aiming radiation beams at the tumor once or twice a day, five days a week, for three to eight weeks. For advanced stages, treatment will usually involve a combination of radiation therapy and chemotherapy.
- Chemotherapy – It is a treatment with drugs that kill cancer cells. Most people get chemotherapy on an outpatient basis, although some require hospitalisation. Outpatient means that the treatment does not require hospital admission and may also be performed outside of it.
- Targeted therapy – This treatment can be effective in both early and advanced stages of cancer. The drugs will bind to specific proteins on cancer cells and interfere with their growth.
- Nutrition – It is an important part of the oral cancer treatment. A lot of treatments make it difficult or painful to swallow and eat, and weight loss and poor appetite are common. Getting the advice of a nutritionist can help you plan a menu that will be gentle on the mouth and throat, and will provide the body with the vitamins, calories, and minerals it needs to heal.
- Keeping the mouth healthy – Finally, keeping the mouth healthy during cancer treatments is extremely crucial. Make sure to keep the mouth moist and the gums and teeth clean.
Side effects of treatment
Side effects of oral cancer or its treatment may include:
- Thickened saliva
- Dry mouth
- Mouth sores
- Changes in taste
- Difficulty in swallowing
- Tooth decay
- Difficulty in chewing or opening the mouth
- Higher risk of gum disease or tooth decay
- Inflammation or pain in the lining of the tongue and mouth
A lot of these side effects happen during the treatment, but some may start after it ends. Either way, most mouth-related side effects are not permanent.
Survivorship and prevention of oral cancer
According to National Cancer Institute, the five-year survival rates for oral cavity cancer is as follows:
- 83 per cent, for localized cancer (that has not spread)
- 64 per cent, for cancer that has spread to nearby lymph nodes
- 38 per cent, for cancer that has spread to other parts of the body
Overall, 60 per cent of people with oral cancer will survive for five years or more. The earlier the stage of diagnosis, the higher the chances of survival. In fact, the five-year overall survival rate in those with stage 1 and 2 oral cancers is typically between 70 to 90 percent. This makes timely diagnosis and treatment all the more important.
Oral cancer is highly preventable and also very treatable, if diagnosed early. It can be prevented by doing the following:
- Do not use tobacco in any form. If you use tobacco, quit today.
- Limit alcohol to no more than one drink per day if you are a woman, or two drinks per day if you are a man.
- Stay out of the sun, especially between 10 am and 4 pm when sunlight is the strongest.
- Always use a lip balm with SPF 30 or higher.
- Eat lots of fruits and vegetables regularly.
Always remember that early detection can improve the chance of successful treatment. Stay healthy and stay safe!