Head & Neck

Oral Cancer

More than half of all head and neck cancers begin in the oral cavity. This area includes the lips, gums, lining inside the lips and cheeks, hard palate (front part of the roof of the mouth), the front two-thirds of your tongue, and the floor of the mouth underneath it, and the retromolar trigone, which is the small space behind each wisdom tooth. Oral cancers usually develop in the thin, flat squamous (SKWAY-mus) cells lining moist surfaces inside the mouth.

Early-stage symptoms may include minor mouth pain, bleeding, jaw swelling or a white or red patch (ulcer) on the gums, tongue or lining of the mouth. Because these symptoms can also signal many other conditions, and there is no recommended routine screening for oral cancers, they are frequently diagnosed at late stage. However, dentists typically screen for cancer at regular six month or annual appointments.

Cancers in the back of the mouth, including the base of the tongue, rear roof of the mouth (soft palate) and tonsils, are considered a type of throat cancer (oropharyngeal cancer).

Some treatments for certain oral cancers may interfere with your ability to speak and/or eat normally, alter your appearance or both. It is very important for you and your doctor to have detailed discussions about the benefits, risks and potential side effects and late effects of every treatment, including quality-of-life issues.

Common Treatments

Some oral cancer treatments may compromise the ability to speak and eat normally, alter appearance, or both. Before weighing treatment options with your doctor, you are encouraged to include a reconstructive surgeon on your medical team. This combined insight will help you be better informed to make decisions about your care.

One or more of the following options, or a clinical trial, may be part of your treatment plan. (See Treatment Options for general descriptions of each treatment type.)

Surgery

Surgery is generally performed to remove small, early-stage tumors of the lip, gums, roof of the mouth, front of the tongue, floor of the mouth and inside the cheeks. Larger tumors and those that have metastasized (spread) to nearby tissue or lymph nodes in the neck may also be removed. The goal of surgery is to remove the tumor; however, your surgeon will also focus on preserving as much normal function as possible.

Several surgical procedures commonly used include the following.

Tumor resection removes the tumor and a margin of healthy tissue surrounding it.

Glossectomy removes all or part of the tongue.

Maxillectomy removes all or part of the hard palate.

Mandibulectomy removes all or part of the jawbone.

Mohs micrographic surgery may be recommended for lip cancers. After removing the tumor, the surgeon removes a tiny fragment of tissue that had surrounded it and examines it under a microscope. The process is repeated until clear margins are seen.

Neck dissection removes some or all of the lymph nodes in the neck when the cancer has spread or if there is a significant risk that cancer will spread to the lymph nodes.

Reconstructive procedures may be recommended to repair or replace removed areas, improve the ability to eat and speak, and help restore appearance as much as possible (see Reconstructive Surgery).

Radiation Therapy

Depending on the type and stage of oral cancer, external-beam radiation therapy (EBRT) or internal radiation therapy (brachytherapy) may be used alone as the main treatment, or it may be used after surgery (adjuvant therapy) to destroy remaining cancer cells. Radiation therapy may also be used alone or with chemotherapy (chemoradiation) to treat affected lymph nodes.

Before beginning any type of radiation therapy, have a thorough dental exam to address existing problems with a dentist experienced in treating people with cancer. If you smoke, be aware that research indicates radiation therapy is more effective in patients who have stopped smoking before beginning treatment.

Immunotherapy

Immune checkpoint inhibitors may be part of your treatment plan if you have recurrent or metastatic oral cancer. Other immunotherapy options may be available in clinical trials.

Targeted Therapy

This may be an option to treat types of oral cancer that contain specific genetic abnormalities, proteins or growth factors. Targeted therapy drugs may be given alone or in combination with chemotherapy or radiation therapy.

Clinical Trials

Various clinical trials involving chemotherapy, immunotherapy, chemoradiation therapy and hyperfractionated radiation therapy, in which a regular dose of radiation is given in smaller doses more than once a day, are underway that may be part of your treatment plan.

If your doctor does not mention clinical trials, ask if any may apply to your diagnosis and whether you may be eligible (see Clinical Trials).

Staging

Diagnosing your type of oral cancer is an important step in creating the best treatment plan for you. Your doctor will perform a thorough exam, imaging studies, blood tests and a biopsy and use these test results to stage the cancer. Staging determines the extent of your cancer, where it is located and whether it has metastasized (spread) to nearby organs, tissues or lymph nodes, or to other parts of your body.

The TNM staging system, developed by the American Joint Committee on Cancer (AJCC), is typically used to classify and stage oral cancer. This system classifies the cancer by tumor (T), node (N) and metastasis (M). The T category describes the size and location of the primary tumor. The N category indicates whether the lymph nodes show evidence of cancer cells. The number and location of these lymph nodes are important because they show how far the disease has spread. The M category describes metastasis (spread of cancer to another part of the body), if any.

Staging Criteria

Once the cancer is classified, an overall stage is assigned. Oral cancer may be Stage 0 through Stage IV. Also known as “in situ,” Stage 0 is a precursor of an invasive cancer. Stages I and II are generally confined to the local area where the cancer is found, and Stage III has spread to the regional lymph nodes in the neck. Stage IV is further divided into Stages IVA, IVB and IVC. Stages IVA and IVB are locally or regionally advanced disease, and Stage IVC has spread to distant sites, such as the liver, lungs or bone.

These basic stages are designed to group patients who have a similar prognosis (outlook). This grouping allows doctors to more accurately predict outcomes for patients depending on the type of treatment they receive. In certain cancers, the stage is also determined by other factors.

Sometimes your doctor may reassess your stage after treatment or if cancer recurs. This is known as restaging. It is rarely done but typically involves the same diagnostic tests used for the original staging. If a new stage is assigned, it’s often preceded by an “r” to denote that it’s been restaged and different from the original stage given at diagnosis.

TNM Classification for Oral Cancer

Classification Definition
Tumor (T)
TX Primary tumor cannot be assessed.
Tis Carcinoma in situ.
T1 Tumor not more than 2 cm, with depth of invasion (DOI) not more than 5 mm. DOI is depth of invasion and not tumor thickness.
T2 Tumor not more than 2 cm, with DOI more than 5 mm
or tumor more than 2 cm but not more than 4 cm, with DOI not more than 10mm; DOI is depth of invasion and not tumor thickness.
T3 Tumor more than 2 cm and not more than 4 cm with DOI more than 10mm;
or tumor more than 4 cm with DOI not more than 10 mm. DOI is depth of invasion and not tumor thickness.
T4 Moderately advanced or very advanced local disease.
  T4a Moderately advanced local disease.
Tumor more than 4 cm with DOI more than 10 mm
or tumor invades adjacent structures only (e.g. through coritical bone of the mandible [lower jawbone] or maxilla [upper jawbone], or involves the maxillary sinus or skin of the face).
DOI is depth of invasion and not tumor thickness.
  T4b Very advanced local disease.
Tumor invades masticator space (located on either side of the face around the jawbones), pterygoid plates, or skull base and/or encases the internal carotid artery.
Node (N)
NX Regional lymph nodes cannot be assessed.
N0 No regional lymph node metastasis.
N1 Metastasis in a single ipsilateral (on the same side) lymph node, 3 cm or smaller in greatest dimension and ENE*(-).
N2 Metastasis in a single ipsilateral (on the same side) lymph node, 3 cm or smaller in greatest dimension and ENE*(+);
or larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(-);
or metastases in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(-);
or in bilateral (on both sides) or contralateral (on the opposite side) lymph node(s), none larger than 6 cm in greatest dimension, ENE(-).
  N2a Metastasis in single ipsilateral (on the same side) node 3 cm or smaller in greatest dimension and ENE*(+);
or a single ipsilateral node larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(-).
  N2b Metastasis in multiple ipsilateral (on the same side) nodes, none larger than 6 cm in greatest dimension and ENE*(-).
  N2c Metastasis in bilateral (on both sides) or contralateral (on the opposite side) lymph node(s), none larger than 6 cm in greatest dimension and ENE*(-).
N3 Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE*(-);
or metastasis in a single ipsilateral (on the same side) node larger than 3 cm in greatest dimension and ENE(+);
or multiple ipsilateral, contralateral (on the opposite side) or bilateral (on both sides) nodes, any with ENE(+);
or a single contralateral node of any size and ENE(+).
  N3a Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE*(-).
  N3b Metastasis in a single ipsilateral (on the same side) node larger than 3 cm in greatest dimension and ENE*(+);
or multiple ipsilateral, contralateral (on the opposite side) or bilateral (on both sides) nodes, any with ENE(+);
or a single contralateral node of any size and ENE(+).
Metastasis (M)
M0 No distant metastasis.
M1 Distant metastasis.
*Extranodal extension (ENE) refers to cancer cells that have spread beyond the lymph node into surrounding tissues.

Staging Oral Cancer

Stage T N M
0 Tis N0 M0
I T1 N0 M0
II T2 N0 M0
III T3
T1, T2, T3
N0
N1
M0
M0
IVA T4a
T1, T2, T3, T4a
N0, N1
N2
M0
M0
IVB Any T
T4b
N3
Any N
M0
M0
IVC Any T Any N M1

Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, Eighth Edition (2017) published by Springer Science+Business Media.

 

 

Key Takeaways

  • The majority of head and neck cancers are found in the mouth.
  • Cancers in the back of the mouth are considered a type of throat cancer.
  • Discuss treatment options in detail to consider potential side effects, late effects and quality-of-life issues.

Additional Resources

 

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