Oral cavity cancer is a serious condition that affects thousands of people in the United States each year. Fortunately, early detection and treatment of this form of head and neck cancer can save lives.
Cancer is a disease associated with accelerated growth of abnormal cells that can start in one location and spread to other sites around the body. Oral cancer is a type of head and neck cancer in which these abnormal cells start in the oral cavity, or mouth.
This type of cancer can affect any tissue in the oral cavity, which consists of:
- The front two-thirds of the tongue
- The gums, also known as the gingiva
- The lining of the inside of the cheeks, also known as the buccal mucosa
- The floor, or bottom, of the mouth beneath the tongue
- The roof of the mouth, also known as the hard palate
- The small area behind the wisdom teeth, known as the retromolar trigone
When discussing this type of cancer, many health professionals also include cancer of the pharynx. The pharynx is the part of the throat behind your mouth and nasal cavity. They use the term “oropharyngeal” to describe conditions affecting the oral cavity and pharynx.
Lip cancer is less common. Approximately 0.1% of men and women will receive a diagnosis of lip cancer at some point in their lifetime.
Continue reading below for more information regarding oral cancer, including:
- Oral Cancer Risk Factors
- Signs and Symptoms of Oral Cavity Cancer
- How Oral Cancer is Diagnosed
- Staging Lip & Oral Cancers
- Treatment Options for Oral Cancer
Risk Factors for Developing Oral Cavity Cancer
A number of factors can increase your risk for cancer of the lip or oral cavity.
Risk factors for lip and oral cavity cancer include the following:
- Smoking or dipping (using smokeless tobacco)
- Heavy alcohol use of more than 21 standard drinks in a week
- HPV infection
- Age
- Sun exposure of the lip
- Diet low in fruits and vegetables
- Gender – men develop this type of cancer about twice as often as women do
Having risk factors does not mean you will automatically develop cancer. Having no risk factors does not guarantee that you will not develop this type of cancer. Your dentist can detect signs of cancer early, so seeing your dentist regularly is important, especially if you are at high risk for developing this type of cancer.
Because risk factors do not determine whether you will develop cancer of the lip or oral cavity, it is important to know the signs and symptoms of the diseases.
Signs and Symptoms of Oral Cancer
Cancer of the lip or oral cavity can cause specific signs and symptoms. It is important to note that many conditions other than cancer can cause these signs and symptoms. You should always contact your doctor or dentist for unexplained oral problems.
Signs and symptoms of this type of cancer include:
- Sores in the mouth or on the lips that will not heal
- Lumps or thickening on the lips, gums, or in the mouth
- Red or white patches on the gums, tongue, or lining of the mouth that do not heal
- Unexplained bleeding in the mouth or lips
- Numbness affecting the lower lip and chin
- An unexpected change in voice
- Loose teeth
- Changes in mouth shape that affect the fit of dentures or mouth guards
- Unexplained pain or difficulty when you chew, swallow, or move your tongue or jaw
- Swelling of your jaw
- An sore throat or a feeling like something is caught in your throat
- Lump in your neck
- A persistent earache
White patches may be pre-cancerous, which means they may turn into cancer someday, although most cases of white patches do not. A mixture of red and white patches in the mouth may turn into cancer; those with a red color have the highest risk for being precancerous or cancerous.
Detection and Diagnosis of Oral Cancer
Your doctor, dentist, or ear, nose and throat specialist can check your mouth and throat for patches, lumps, swelling, or other signs and symptoms of cancer of the oral cavity. Your healthcare professional will look carefully at the roof of your mouth, the back of your throat, your tongue, and the inside of your cheeks and lips. The practitioner will also check the floor of your mouth and your lymph nodes. Your lymph nodes are glands on the sides of your neck.
In some cases, the healthcare professionals will use a small, long-handled mirror or lighted tube to see the back of your nose, tongue, and throat. Your oncologist or dentist may recommend a CT scan or MRI imaging to look for a hidden tumor or to determine the stage of cancer.
If your primary care provider suspects cancer, they may order a biopsy. During a biopsy, the provider removes a small piece of tissue for examination in a medical laboratory. Providers often administer local anesthesia when performing biopsies of the oral cavity, but they do sometimes perform these biopsies under general anesthesia. A biopsy is the only sure way to know if abnormal tissue is cancerous. If your biopsy comes back positive for cancer cells, your doctor may recommend more tests to determine if the cancer is spreading to other parts of the body.
Tests Used to Diagnose Oral Cavity Cancer
Some of the tests used in assessing the extent of the cancer might include one more of the following:
- X-rays: These images can help your cancer specialist determine if cancer has spread to your jaw, chest or lungs
- Barium swallow: Involves drinking a liquid that contains barium, which helps abnormal cells in your digestive tract show up on x-rays
- CT scan: An x-ray machine linked to a computer that takes a series of detailed pictures of any tumors in your mouth, neck, throat, lungs, or somewhere else in your body
- MRI: A type of imaging system that uses powerful magnets rather than x-rays to make detailed pictures of any tumors in your mouth, neck, throat, lungs, or somewhere else in your body
- Endoscopy: A test in which your oncologist uses a thin, flexible tube attached to a light and a camera to look into your throat and upper digestive tract; the endoscopy tube also includes a tool that your oncologist can use to remove tissue or lymph node samples for biopsy
- PET scan: A type of imaging that uses an injection of a small amount of radioactive sugar that emits signals that the PET scanner picks up to create an image; cancer cells absorb sugar more quickly than do healthy cells, so cancer cells show up as brighter than surrounding cells on a PET scan
- Exfoliative cytology: A medical provider uses a piece of cotton, a brush, or a small wooden stick to scrape cells gently from your lips, tongue, mouth or throat for evaluation in a medical laboratory
- Bone scan: An imaging test that helps your oncologist look for rapidly dividing cancer cells in your bones
Staging Oral Cavity Cancer
After an oral cancer diagnosis, the next step will be to determine the stage (extent). The staging system most often used for oral cavity cancer is the American Joint Committee on Cancer (AJCC) TNM system, which is based on 3 key pieces of information:
- Tumor (T): the size and primary location of the tumor
- Node (N): if the cancer has spread to the lymph nodes
- Metastasis (M): whether the cancer has metastasized (spread) to other areas of the body
Your cancer can be stage 0, 1, 2, 3, or 4. The lower the number, the less the cancer has spread. A higher number, like stage 4, means a more serious cancer that has spread from where it started to other parts of the body.
T Categories for Staging Oral Cancer
"T" plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Tumor size is measured in millimeters (mm) and centimeters (cm). Stage may also be divided into smaller groups that help describe the tumor in even more detail. The specific tumor stage information is as follows:
- TX: The primary tumor cannot be evaluated.
- Tis: A very early cancer, called carcinoma in situ, where cancer cells are found only in 1 layer of tissue.
- T1: The tumor is 2 cm or less. It has invaded nearby tissues to a depth of 5 mm or less (called depth of invasion).
- T2: The tumor is 2 cm or smaller, and the depth of invasion is between 5 and 10 mm. Or, the tumor is larger than 2 cm but not larger than 4 cm, and the depth of invasion is 10 mm or less.
- T3: The tumor is greater than 4 cm, or it is any tumor with a depth of invasion greater than 10 mm.
- T4: Tumor is considered a moderately advanced or very advanced local disease.
- T4a: The tumor has invaded nearby structures in the mouth, such as the jaw, sinuses, or skin of the face.
- T4b: The tumor has invaded the muscles and bones that form the mouth or the base of the skull, and/or it encases the internal arteries.
N Categories for Staging Oral Cancer
There are 2 methods of categorizing N in the TNM system: clinical and pathological. Clinical N is used for patients who have not received a neck dissection. Pathological N is used for those who have had a lymph node dissection. When cancer has spread through a lymph node and into the tissues directly surrounding it, it is called extranodal extension (ENE).
Clinical
- NX: The regional lymph nodes cannot be evaluated.
- N0: No evidence of cancer in the regional lymph nodes.
- N1: The cancer has spread to a single lymph node on the same side as the primary tumor, and the cancer found in the node is 3 cm or smaller. There is no ENE.
- N2a: The cancer has spread to a single lymph node on the same side as the primary tumor and is greater than 3 cm but less than 6 cm. No ENE is present.
- N2b: The cancer has spread to more than 1 lymph node on the same side as the primary tumor, and none measures larger than 6 cm. No ENE is present.
- N2c: Cancer has spread to more than 1 lymph node on either side of the body, and none measure greater than 6 cm. No ENE is present.
- N3a: Cancer is found in a lymph node and measures greater than 6 cm. No ENE is present.
- N3b: ENE is present in any lymph node.
Pathological
- NX: Regional lymph nodes cannot be evaluated.
- N0: There is no evidence of cancer in the regional lymph nodes.
- N1: Cancer has spread to a single lymph node on the same side as the primary tumor, and the cancer found in the node measures 3 cm or less. No ENE is present.
- N2a: Cancer has spread to 1 lymph node and is 3 cm or smaller, but no ENE is present. Or, cancer has spread to a single lymph node on the same side as the primary tumor and is greater than 3 cm but no larger than 6 cm, and no ENE is present.
- N2b: Cancer has spread to more than 1 lymph node on the same side as the primary tumor, and none measures greater than 6 cm. No ENE is present.
- N2c: Cancer has spread to more than 1 lymph node on either side of the body, and none measure greater than 6 cm. No ENE is present.
- N3a: Cancer is found in a lymph node and is greater than 6 cm. No ENE is present.
- N3b: ENE is present in a single lymph node on the same side as the primary tumor, and it is greater than 3 cm. Or, cancer has spread to many lymph nodes, and at least 1 has ENE. Or, ENE is present in a single lymph node on the opposite side of the primary tumor that is 3 cm or less.
M Categories for Staging Oral Cancer
- M0: The cancer has not spread to other parts of the body.
- M1: The cancer has spread to other parts of the body.
Oral Cancer Stage Grouping
The T, N, and M information is combined to determine what stage the cancer is.
Stage I: Tumor is 2 cm or smaller, and the depth of invasion is 5 mm or less. It has not spread to lymph nodes or other parts of the body (T1, N0, M0).
Stage II: Tumor is 2 cm or smaller, and the depth of invasion is between 5 and 10 mm. Or, the tumor is greater than 2 cm but not greater than 4 cm, and the depth of invasion is 10 mm or less. It has not spread to lymph nodes or other parts of the body (T2, N0, M0).
Stage III: One of the following applies:
- Tumor is greater than 4 cm, or it is any tumor with a depth of invasion greater than 10 mm. It has not spread to lymph nodes or other parts of the body (T3, N0, M0).
- Tumor is any size, but it has not invaded nearby structures of the oral cavity. There is cancer in a single lymph node on the same side as the primary tumor, and the cancer is 3 cm or less. No ENE is present. Cancer has not spread to other parts of the body (T1 to T3, N1, M0).
Stage IVA: One of the following applies:
- Tumor has invaded nearby structures in the mouth, such as the jaw, sinuses, or skin of the face. If cancer has spread to a lymph node, it is to only 1 node on the same side as the primary tumor, and the cancer is 3 cm or less, with no ENE. Cancer has not spread to other parts of the body (T4a, N0 or N1, M0).
- Tumor is small or it may have invaded nearby structures. Cancer has spread to 1 or more lymph nodes, but none is greater than 6 cm. There is no ENE. Cancer has not spread to other parts of the body (T1 to T4a, N2, M0).
Stage IVB: One of the following applies:
- Tumor is any size. The cancer is found in a lymph node and is greater than 6 cm, but there no ENE is present; or ENE is present in any lymph node. Cancer has not spread to other parts of the body (any T, N3, M0).
- Tumor has invaded the muscles and bones that form the mouth or the base of the skull, and/or it encases the internal arteries. The cancer may involve the lymph nodes, but it has not spread to other parts of the body (T4b, any N, M0).
Stage IVC: Cancer has spread to other parts of the body (any T, any N, M1).
Oral Cancer Treatment Options
Oncologists usually treat early oral cancer with surgery or radiation therapy. They treat advanced cases with a combination of treatments, such as radiation and chemotherapy at the same time.
Oncologists sometimes recommend targeted therapy. Chemotherapy can harm healthy cells as it kills cancer cells. Targeted therapy is different in that the drugs used precisely identify and attack only cancer cells, and leaves other cells unharmed.
The type of treatment you receive depends largely on your overall health, the location in your mouth or throat where the cancer began, the size of the tumor, and whether the cancer has spread.
Surgery
Surgery for this type of cancer removes the tumor. In some cases, the surgeon also removes the lymph nodes in the neck and other tissues in the mouth and neck. Surgery may be the sole treatment, but oncologists often combine it with radiation therapy. Depending on the location of the tumor, you may need follow-up plastic surgery.
Radiation therapy
Radiation therapy uses high-energy to kill oral cancer cells. This treatment is an option for people who cannot have surgery or who have small tumors. Cancer doctors sometimes recommend radiation therapy to shrink the tumor prior to surgery. Radiation therapy is also useful for destroying any cancer cells remaining in the area after surgery.
Types of radiation therapy
There are two main types of radiation therapy for this type of cancer. A patient may undergo one type of radiation therapy or both.
- External radiation therapy: A machine produces the radiation. Some cancer treatment centers offer intensity-modulated radiation therapy (IMRT) that uses a computer that manipulates the shape of the radiation beams to more closely match the shape of the tumor and lessen the damage to healthy tissue nearby. You will undergo the treatment once or twice a day, usually for 5 days a week for several weeks. Each treatment takes only a few minutes.
- Internal radiation therapy: The radiation comes from radioactive material in “seeds,” wires or tubes placed near the cancerous tissue. This type of therapy is less common for cancer of the oral cavity.
Chemotherapy
Chemotherapy uses drugs to kill cancer cells. Cancer care specialists usually administer chemotherapy drugs through an intravenous (IV) needle. The drugs enter the bloodstream and travel throughout the body to reach the cancer cells eventually. In some cases, the oncologist may suggest undergoing chemotherapy and radiation therapy.
Targeted therapy
Targeted therapy uses drugs and techniques that destroy only cancer cells and leaves other cells unharmed. Oncologists sometimes recommend targeted therapy alongside radiation treatments or chemotherapy.
Cetuximab (Erbitux) was the first targeted therapy approved by the FDA for the treatment of oral cancer. Cetuximab works by binding to oral cancer cells then interfering with cancer cell growth and spread. You may receive cetuximab through a vein once a week for several weeks at Willamette Valley Cancer Institute.
