Oral Cancer Stages

A cancer’s stage refers to how large the primary tumor is and how far the cancer has spread in the patient’s body. Knowing the stage helps the care team understand the disease and develop an appropriate treatment plan. It also impacts the patient’s prognosis, or chance for a successful treatment.

TNM stages

The TNM staging system is used for most cancers.

TNM staging describes cancer based on three main factors:

• The size of the primary tumor (T) and whether it has invaded nearby tissues.
• The cancer’s spread to nearby lymph nodes (N).
•  Whether the cancer has metastasized (M), or spread, to distant parts of the body.

Each TNM factor is assigned a number that reflects the extent of the cancer. Tumors (T) are scored between 1-4, nodes (N) 1-3, and metastasis (M) 0-1.

After all diagnostic and staging procedures are performed, your doctor should know the TNM stage of your cancer and be able to explain how this stage impacts your treatment and prognosis.

0 to IV stages

Often, TNM staging can be simplified into stages four stages (I-IV). For some cancers, there is also a stage 0. Larger numbers mean the cancer is more advanced and is generally more difficult to treat.

• Stage 0 reflects the presence of abnormal cells that have not spread to tissue that is immediately nearby. Stage 0 is considered precancerous, though it could become cancer in the future. This stage is also called “in-situ,” which means “in its original place.” Not all cancers have a stage 0.
• Stage I cancers are typically small and confined to the area where they began.
• Stage II and Stage III cancers have spread to nearby tissue and/or lymph nodes.
• Stage IV cancer has spread to distant areas of the body. This is also called metastatic cancer. Stage IV cancer often cannot be cured, but frequently can be managed like a chronic disease.

Oral cancer 0-IV stages

Source: National Cancer Institute

Stage 0 (Carcinoma in Situ)

In stage 0, abnormal cells are found in the lining of the lips and oral cavity. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I

In stage I, cancer has formed. The tumor is 2 centimeters or smaller and the deepest point of tumor invasion is 5 millimeters or less.

Stage II

In stage II, the tumor:

• is 2 centimeters or smaller and the deepest point of tumor invasion is greater than 5 millimeters; or
• is larger than 2 centimeters but not larger than 4 centimeters and the deepest point of tumor invasion is 10 millimeters or less.

Stage III

In stage III, the tumor:

• is larger than 2 centimeters but not larger than 4 centimeters and the deepest point of tumor invasion is greater than 10 millimeters; or
  
• is larger than 4 centimeters and the deepest point of tumor invasion is 10 millimeters or less; or
  
• has spread to one lymph node that is 3 centimeters or smaller, on the same side of the neck as the primary tumor.
  

Stage IV 

Stage IV is divided into stages IVA, IVB, and IVC.

In stage IVA, the tumor:

• is larger than 4 centimeters and the deepest point of tumor invasion is greater than 10 millimeters; or cancer has spread to the outer surface of the upper or lower jawbone, into the maxillary sinus, or to the skin of the face. The cancer may have spread to one lymph node that is 3 centimeters or smaller, on the same side of the neck as the primary tumor; or
  
• is any size or cancer has spread to the outer surface of the upper or lower jawbone, into the maxillary sinus, or to the skin of the face. Cancer has spread:
  
• to one lymph node that is 3 centimeters or smaller, on the same side of the neck as the primary tumor, and cancer has spread through the outside covering of the lymph node into nearby connective tissue; or
  
• to one lymph node that is larger than 3 centimeters but not larger than 6 centimeters, on the same side of the neck as the primary tumor; or
  
• to multiple lymph nodes that are not larger than 6 centimeters, on the same side of the neck as the primary tumor; or
  
• to multiple lymph nodes that are not larger than 6 centimeters, on the opposite side of the neck as the primary tumor or on both sides of the neck.

In stage IVB, the tumor:

• has spread to one lymph node that is larger than 6 centimeters; or
• has spread to one lymph node that is larger than 3 centimeters, on the same side of the neck as the primary tumor, and cancer has spread through the outside covering of the lymph node into nearby connective tissue; or
  
• has spread to one lymph node of any size on the opposite side of the neck as the primary tumor, and cancer has spread through the outside covering of the lymph node into nearby connective tissue; or
  
• has spread to multiple lymph nodes anywhere in the neck, and cancer has spread through the outside covering of any lymph node into nearby connective tissue; or
  
• has spread further into the muscles or bones needed for chewing, or to the part of the sphenoid bone behind the upper jaw, and/or to the carotid artery near the base of the skull. Cancer may have also spread to one or more lymph nodes of any size, anywhere in the neck.
  

In stage IVC, the tumor has spread beyond the lip or oral cavity to other parts of the body, such as the lung, liver, or bone.