Head & Neck

Oral Cancer

The oral cavity area (known as the mouth) 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 the tongue, the floor of the mouth underneath it, and the retromolar trigone, which is the small space behind each wisdom tooth.



More than half of all head and neck cancers begin in the oral cavity. Oral cancers usually develop in the thin, flat squamous (SKWAY-mus) cells lining moist surfaces inside the mouth and are called squamous cell carcinoma. 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 (oropharyngeal) cancer.



Because the symptoms of oral cancer can also signal many other conditions, they are frequently diagnosed at a late stage. However, dentists typically screen for cancer at regular six month or annual appointments.



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.


Treatment Options

As you discuss your treatment plan with your doctor, keep in mind that treating oral cancer may affect the ability to speak and eat normally and may alter appearance. As a result, you are encouraged to discuss reconstructive options as well. Many surgeons that remove head and neck cancer are also trained in reconstruction and can expertly perform both parts of the surgery.



Your treatment plan may include one or more of the following options.


    Surgery

    Surgery is typically the recommended treatment for oral cavity cancers. It is 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. It may also be used to remove larger tumors and those that have metastasized (spread) to nearby tissue or lymph nodes in the neck. The goal of surgery is to remove the tumor; however, your surgeon will also focus on preserving as much function as possible. Various procedures and techniques may include the following.



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



    Glossectomy removes all or part of the tongue. A partial glossectomy removes less than half of the tongue, a hemiglossectomy removes half of the tongue, and a subtotal or total glossectomy removes most or all of the tongue.



    Maxillectomy removes all or part of the hard palate.



    Mandibulectomy removes all or part of the jawbone.



    Composite resection is common in treating advanced oral cancers. It may involve the removal of multiple areas affected by cancer, such as part of the jaw, tongue and floor of the mouth.



    Mohs micrographic surgery may be recommended for some types of lip cancer. 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. This type of procedure is performed by a dermatologist.



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


    Radiation Therapy

    Radiation therapy in the form of external-beam radiation therapy or internal radiation therapy (brachytherapy) may be recommended. It may be used alone if you are not a candidate for surgery (due to other medical problems or the extent of the cancer). This does not cure the cancer but may slow down the growth and spread, and alleviate symptoms.



    Radiation is typically used after surgery as adjuvant therapy to destroy remaining cancer cells and reduce the risk of the cancer recurring. Radiation therapy may also be used alone or with chemotherapy (chemo-radiation) for cancer that has a higher risk of recurring.



    Radiation therapy to the oral cavity can affect your teeth. Before beginning this type of treatment, you will be required to 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.


    Drug Therapy

    Drug therapy may be used alone or with other therapies.

    Chemotherapy can be used for oral cavity cancer if you are not a candidate for surgery. This can be given with the goal of slowing down the growth and spread of the cancer. It is more commonly used as adjuvant treatment following surgery if your cancer has aggressive features and a higher risk of returning.

    Immunotherapy in the form of immune checkpoint inhibitors may be part of your treatment plan if you have recurrent or metastatic oral cancer. The doctor will test for the tumor’s PD-L1 expression, which may indicate whether the tumor could respond to immunotherapy. If expression is more than 1 percent, the tumor is considered to be PD-L1 positive and immunotherapy alone may be used. If PD-L1 is negative, immunotherapy and traditional chemotherapy are often combined for patients who have recurrent/metastatic cancer.

    Targeted therapy may be an option to treat types of oral cancer that contain specific genetic abnormalities, proteins or growth factors. Targeted therapy in the form of epidermal growth factor receptor (EGFR) inhibitors may be used in combination with radiation therapy. Targeted therapy drugs may be given alone or in combination with chemotherapy or radiation therapy.

    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.

    Illustrated Stages of Oral Cancer

     

    Back to Head & Neck Cancer