Making an educated treatment decision begins with knowing the stage, or progression, of the disease. The stage of oral cancer is one of the most important factors in evaluating treatment options.
Our cancer doctors use a variety of diagnostic tests to evaluate oral cancer and develop an individualized treatment plan. If you have been recently diagnosed, we will review your pathology to confirm you have received the correct diagnosis and staging information, and develop a treatment plan tailored to you and your needs. If you have a recurrence, we will perform comprehensive testing and recommend a treatment approach that is personalized to you and your cancer type and stage.
We stage oral cancer using the American Joint Committee on Cancer’s TNM system, a commonly accepted method based on three key components:
T (tumor): This describes the size of the original tumor.
N (node): This indicates whether the cancer is in the lymph nodes.
M (metastasis): This refers to whether the cancer has spread to other parts of the body.
A number (0-4) or the letter X is assigned to each factor. A higher number indicates increasing severity. For instance, a T1 score indicates a smaller tumor than a T2 score. The letter X means the information could not be assessed.
Once the T, N and M scores have been assigned, an overall stage is determined.
T categories for oral cavity cancer
These measurements refer to the primary oral cancer tumor.
TX: Primary tumor cannot be assessed; information not known.
TO: No evidence of a primary tumor has been found.
Tis: Carcinoma in situ has been diagnosed, meaning the disease is still localized, or contained within the top layers of cells lining the oral cavity. Cancer cells have not invaded the deeper layers of oral tissue.
T1: Tumor is 2 cm across or smaller.
T2: Tumor is larger than 2 cm across, but smaller than 4 cm.
T3: Tumor is larger than 4 cm across.
T4 is divided into two subgroups:
- T4a: The tumor is growing into nearby structures. At this stage, the oral cancer is called a moderately advanced local disease. The areas to which cells have spread vary according to the type of oral cancer.
- For oral cavity cancers, the tumor is growing into nearby structures, such as the bones of the jaw or face, deep muscle of the tongue, skin of the face, or maxillary sinus.
- For lip cancers, the tumor is growing into nearby bone, the inferior alveolar nerve (the nerve to the jawbone), the floor of the mouth, or the skin of the chin or nose.
- T4b: The tumor has grown through nearby structures and into deeper areas or tissues. At this stage, the cancer is called very advanced local disease, and may include any of the following conditions:
- The tumor is growing into other bones, such as the pterygoid plates (in the skull) and/or the skull base. This type of spreading may occur with any oral cancer.
- The tumor surrounds the internal carotid artery. This type of spreading may occur with any oral cancer.
- For lip and oral cavity cancers: the tumor is growing into an area called the masticator space.
N categories for oral cavity cancers
NX: Nearby lymph nodes cannot be assessed; information not known.
N0: The oral cancer has not spread to nearby lymph nodes.
N1: The cancer has spread to one lymph node on the same side of the head or neck as the primary tumor. This lymph node is smaller than 3 cm across.
N2: This category is divided into these subgroups:
- N2a: The oral cancer has spread to one lymph node on the same side as the primary tumor, and the lymph node measures 3-6 cm across.
- N2b: The cancer has spread to two or more lymph nodes on the same side as the primary tumor. No lymph nodes are larger than 6 cm across.
- N2c: The oral cancer has spread to one or more lymph nodes on both sides of the neck or on the side opposite the primary tumor. No lymph nodes are larger than 6 cm across.
- N3: The cancer has spread to a lymph node that measures more than 6 cm across.
M categories for oral cavity cancers
M0: No distant spread has been detected.
M1: The oral cancer has spread to distant sites outside the head and neck region (for example, the lungs, liver or bones).
Stages of oral cancer:
Stage 0: A stage 0 oral cancer tumor means the cancer is only growing in the epithelium, the outermost layer of tissue in the oral cavity or oropharynx. No cancer cells are present in deeper layers of tissue, nearby structures, lymph nodes or distant sites (carcinoma in situ).
Stage 1 oral cancer: A stage 1 oral cancer tumor means the primary tumor is 2 cm across or smaller, and no cancer cells are present in nearby structures, lymph nodes or distant sites.
Stage 2 oral cancer: A stage 2 oral tumor measures 2 cm to 4 cm across, and no cancer cells are present in nearby structures, lymph nodes or distant sites.
Stage 3 oral cancer: A stage 3 oral tumor means one of the following:
- The oral tumor is larger than 4 cm across, and no cancer cells are present in nearby structures, lymph nodes or distant sites.
- The oral tumor is any size but has not grown into nearby structures or distant sites. However, cancer cells are present in one lymph node, which is located on the same side of the head or neck as the primary tumor and is smaller than 3 cm across.
Stage 4 oral cancer: There are three categories in this stage:
- In stage 4A oral cancer, one of the following applies:
- T4a, with or without lymph node involvement: The oral cancer tumor is growing into nearby structures and may be any size. Cancer cells may not be present in the lymph nodes, or they may have spread to one lymph node, which is located on the same side of the head or neck as the primary tumor and is smaller than 3 cm across. Cancer has not spread to distant sites.
- N2, with any size tumor: The tumor is any size and may or may not have invaded nearby structures, it has not spread to distant sites, and one of the following is true:
- Cancer cells are present in one lymph node, are located on the same side of the head or neck as the primary tumor, and measure 3-6 cm across (N2a).
- Cancer cells are present in one lymph node on the opposite side of the head or neck, and measure less than 6 cm across (N2b).
- Cancer cells are present in two or more lymph nodes, are smaller than 6 cm across, and are located on either side of the head or neck (N2c).
- In stage 4B oral cancer, one of the following applies:
- T4b, any N, M0: The tumor has invaded deeper areas and/or tissues. It may or may not have spread to lymph nodes and has not spread to distant sites.
- Any T, N3, M0: The tumor is any size and may or may not have grown into other structures. It has spread to one or more lymph nodes larger than 6 cm across, but has not spread to distant sites.
- Stage 4C oral cancer, with any T, and any N, M1: There is metastasis with a tumor of any size or lymph node involvement. Cancer cells have spread to distant sites, most often the lungs.
Next topic: How is oral cancer diagnosed?
