Staging of Oral Cancer

Cancer staging is the process of determining the extent of the disease and how far the cancer has spread. Doctors use information about the stage of the cancer to develop a treatment plan and evaluate the patient's prognosis (expected outcome). Oral cancer and oropharyngeal cancer are staged using the TNM Staging System, which was developed by the American Joint Committee on Cancer (AJCC).

In the TNM system, T refers to the size of the tumor and which oral tissues are affected; N refers to the involvement of nearby lymph nodes in the neck area; and M refers to whether or not the cancer has spread (metastasized) to other areas, such as the lungs, liver, or bones.

Tumor classifications for oral and oropharyngeal cancer include the following:

  • TX: primary tumor cannot be assessed
  • T0: no evidence of primary tumor
  • Tis: tumor confined to the outer layer of tissue
  • T1: primary tumor is 2 cm or smaller in diameter (less than ¾ inch)
  • T2: tumor is larger than 2 cm but smaller than 4 cm (1 ½ inch)
  • T3: primary tumor is larger than 4 cm
  • T4: tumor has invaded nearby structures (e.g., bone, muscle, facial skin, sinuses, larynx)

Lymph node classifications for oral and oropharyngeal cancer include the following:

  • NX: lymph nodes cannot be assessed
  • N0: cancer has not spread to lymph nodes
  • N1: cancer has spread to one lymph node, which is smaller than 3 cm in diameter, located on the same side of the head as the primary tumor
  • N2:
    • N2a: cancer has spread to one lymph node, which is larger than 3 cm but smaller than 6 cm, on the same side of the head
    • N2b: cancer has spread to more than one lymph node on the same side but none are larger than 6 cm in diameter
    • N2c: cancer has spread to one or more lymph node on the opposite side of the head or on both sides but none is larger than 6 cm
  • N3: primary tumor has spread to one or more lymph nodes that are larger than 6 cm

Metastasis classifications for oral cancer include the following:

  • MX: cancer spread to distant sites cannot be assessed
  • M0: cancer has not spread to distant sites
  • M1: cancer has spread outside the head and neck

Once the tumor, lymph node, and metastasis factors have been evaluated, the oral cancer is assigned a stage:

Stage 0 oral cancer is confined to the outer layer of tissue and has not spread to deeper tissue, nearby structures and lymph nodes, or distant sites (e.g., Tis, N0, M0).

In stage I oral cancer, the tumor is 2 cm or less in diameter (less than ¾ of an inch) and has not spread to nearby structures and lymph nodes or distant sites (e.g., T1, N0, M0).

In stage II oral cancer, the tumor is larger than 2 cm, but smaller than 4 cm in diameter and has not spread to nearby structures and lymph nodes or distant sites (e.g., T2, N0, M0).

Stage III oral cancer involves one of the following:

  • Tumor larger than 4 cm that has not spread to nearby structures, lymph nodes, or distant sites (e.g., T3, N0, M0) or
  • Tumor of any size that has not invaded nearby structures, but has spread to only one lymph node, which is smaller than 3 cm in diameter, on the same side of the head, and has not spread to distant sites (e.g., T1, N1, M0; T2, N1, M0; T3, N1, M0)

Stage IVA oral cancer involves one of the following:

  • Tumor of any size has invaded nearby structures and has not spread to the lymph nodes, or has spread to only one lymph node, which is smaller than 3 cm in diameter, on the same side of the head, and has not spread to distant sites (e.g., T4, N0, M0; T4, N1, M0)
  • Tumor of any size may or may not have spread to nearby structures and has spread to one lymph node, which is between 3 and 6 cm in diameter, on the same side of the head, or to one lymph node on the opposite side of the head (less than 6 cm in diameter), or to more than one lymph node on either side of the head and all are less than 6 cm in diameter, and has not spread to distant sites (e.g., any T, N2, MO)

In stage IVB oral cancer, the tumor of any size may or may not have spread to nearby structures and has spread to one or more lymph nodes, which are larger than 6 cm in diameter, but has not spread to distant sites (e.g., any T, N3, M0).

Stage IVC oral cancer involves a tumor of any size that may or may not have spread to lymph nodes and has spread to a distant site (e.g., any T, any N, M1).

Stage 0 cancer carries the most favorable prognosis and stage IVC cancer carries the least favorable prognosis. Recurrent oral cancer, which is cancer that returns after treatment, may affect the mouth or throat (called local recurrence), may affect the lymph nodes in the neck (called regional recurrence), or may affect another area of the body (called distant recurrence).

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 06 May 2009

Last Modified: 02 Dec 2011