© 2005-2012 American Society of Clinical Oncology (ASCO). All rights reserved worldwide.
Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer’s stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient’s prognosis (chance of recovery). There are different stage descriptions for different types of cancer.
There is no standard staging system used for AdCC, but often the staging system for a major salivary gland tumor is used.
One tool that doctors use to describe the stage is the TNM system. This system judges three factors: the size of the tumor itself, whether the tumor has spread to the lymph nodes around the tumor, and if the tumor has spread to other parts of the body. The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero) and stages I through IV (one through four). The stage provides a common way of describing the cancer so doctors can work together to plan the best treatments.
TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:
- How large is the primary tumor and where is it located? (Tumor, T)
- Has the tumor spread to the lymph nodes? (Node, N)
- Has the cancer metastasized to other parts of the body? (Metastasis, M)
Tumor. Using the TNM system, the "T" plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Some stages are divided into smaller groups that help describe the tumor in even more detail. Specific tumor stage information is listed below.
TX: The primary tumor cannot be evaluated.
T0: No evidence of a tumor is found.
T1: The tumor is small, 2 centimeters (cm) at its widest dimension, and noninvasive.
T2: The tumor is larger, between 2 cm and 4 cm, but noninvasive.
T3: The tumor is larger than 4 cm, but not larger than 6 cm, and has spread beyond the salivary gland. However, the tumor does not affect the seventh nerve, which is the facial nerve that controls such expressions as smiles or frowns.
T4a: The tumor has invaded the skin, jawbone, ear canal, and/or facial nerve.
T4b: The tumor has invaded the skull base and/or the nearby bones and/or encases the arteries.
Node. The “N” in the TNM staging system is for lymph nodes, the tiny, bean-shaped organs that help fight infection. For AdCC, lymph nodes near the head and neck are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes.
NX: The neck has undergone an intervention that prevents the status of lymph nodes from being evaluated.
N0: There is no evidence of cancer in the regional nodes.
N1: The cancer has spread to a single node on the same side as the primary tumor, and the cancer found in the node is 3 cm or smaller.
N2: Describes any of these conditions:
N2a: The cancer has spread to a single lymph node on the same side as the primary tumor and is larger than 3 cm, but not larger than 6 cm.
N2b: The cancer has spread to more than one lymph node on the same side as the primary tumor, and no tumor measures larger than 6 cm.
N2c: The cancer has spread to more than one lymph node on either side of the body, and no tumor measures larger than 6 cm.
N3: The cancer found in the lymph nodes is larger than 6 cm.
Distant metastasis. The "M" in the TNM system describes cancer that has spread to other parts of the body.
MX: Distant metastasis cannot be evaluated.
M0: The cancer has not spread to other parts of the body.
M1: The cancer has spread to other parts of the body.
Cancer stage grouping
Doctors assign the stage of the cancer by combining the T, N, and M classifications.
Stage I: This stage describes a noninvasive tumor (T1, T2) with no spread to lymph nodes (N0) and no distant metastasis (M0).
Stage II: This stage describes an invasive tumor (T3) with no spread to lymph nodes (N0) or distant metastasis (M0).
Stage III: This stage describes a smaller tumor (T1, T2) that has spread to regional lymph nodes (N1) but shows no sign of metastasis (M0).
Stage IVA: This stage describes any invasive tumor (T4a) that either has no lymph node involvement (N0) or has spread to only a single, same-sided lymph node (N1), but with no metastasis (M0). It is also used to describe a T3 tumor with one-sided nodal involvement (N1) but no metastasis (M0), or any tumor (any T) with extensive nodal involvement (N2) but no metastasis (M0).
Stage IVB: This stage describes any cancer (any T) with more extensive spread to lymph nodes (N2, N3) and no metastasis (M0).
Stage IVC: This stage describes any cancer (any T, any N) with distant metastasis (M1).
Recurrent: Recurrent cancer is cancer that comes back after treatment. If there is a recurrence, the cancer may need to be staged again (called re-staging) using the system above.
Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer-Verlag New York, www.cancerstaging.net.