Staging is the process of finding out how far a cancer hasspread. The stage of salivary gland cancer is one of the most important factors in selecting treatment options and estimating a patient's outlook for recovery and outlook (prognosis).

The stage of a cancer is determined from the results of physical exams, imaging tests (ultrasound, CT or MRI scan, etc.) and other tests, which are described in the section "How is salivary gland cancer diagnosed?", and by the results of surgery if it has been done.

The American Joint Committee on Cancer (AJCC) TNM system

A staging system is a standardized way for the cancer care team to summarize information about how far a cancer has spread. The most common system used to describe the stages of salivary gland cancers is the TNM system of the American Joint Committee on Cancer (AJCC). This system contains 3 key pieces of information:

• T describes the size of the primary tumor and whether it has invaded into nearby organs or tissues.
• N describes whether the cancer has spread to nearby (regional) lymph nodes (bean-sized collections of immune system cells located throughout the body).
• M indicates whether the cancer has metastasized (spread) to other organs of the body. (The most common site of distant salivary gland cancer spread is the lungs.)

Numbers or letters appear after T, N, and M to provide more details about each of these factors:

• The numbers 0 through 4 indicate increasing severity.
• The letter X means "cannot be assessed" because the information is not available.

T groups for major salivary gland cancers

N groups for major salivary gland cancers

• N2a: The cancer has spread to 1 lymph node on the same side as the primary tumor.  The lymph node is larger than 3 cm but not larger than 6 cm (about 2½ inches) across.
• N2b: The cancer has spread to more than 1 lymph node on the same side as the primary tumor, none of the lymph nodes are larger than 6 cm across.
• N2c: The cancer has spread to 1 or more lymph nodes, none larger than 6 cm across, either on the side opposite the primary tumor or on both sides of the neck.

M groups for major salivary gland cancers

Stage grouping

Once the T, N, and M categories have been assigned, this information is combined in a process called stage grouping to assign an overall stage. The stage is expressed in Roman numerals from I (the least advanced) to IV (the most advanced). Some stages are subdivided with letters.

Stage I: T1, N0, M0: The tumor is no more than 2 cm (about ¾ inch) across and is not growing into nearby tissues (T1). It has not spread to nearby lymph nodes (N0) or distant sites (M0).

Stage II: T2, N0, M0: The tumor is larger than 2 cm but is no larger than 4 cm across and is not growing into nearby tissues (T2). It has not spread to nearby lymph nodes (N0) or distant sites (M0).

Stage III: Either of the following:

T3, N0, M0: The tumor is larger than 4 cm across and/or is growing into nearby soft tissues (T3). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).

OR

T1 to T3, N1, M0: The tumor is any size and may have grown into nearby soft tissues (T1 to T3). The cancer has spread to one lymph node on the same side of the head or neck as the primary tumor, but the lymph node is no larger than 3 cm across (N1). The cancer has not spread to distant sites (M0).

Stage IVA: Either of the following:

T4a, N0 or N1, M0: The tumor is any size but invades nearby structures such as the jaw bone, skin, ear canal, and/or facial nerve (T4a). It may or may not have spread to one lymph node (no larger than 3 cm across) on the same side of the head or neck as the primary tumor (N0 or N1). The cancer has not spread to distant sites (M0).

OR

T1 to T4a, N2, M0: The tumor is any size and may or may not invade nearby soft tissues or structures such as the jaw bone, skin, ear canal, and/or facial nerve (T1 to T4a). The cancer has spread to more than one lymph node, to a lymph node larger than 3 cm across, or to lymph nodes on the other or both sides of the neck. None of the lymph nodes are larger than 6 cm across (N2). The cancer has not spread to distant sites (M0).

Stage IVB: Either of the following:

T4b, Any N, M0: The tumor is any size and invades nearby structures such as the base of the skull or other bones nearby, or it surrounds the carotid artery (T4b). The cancer may or may not have spread to nearby lymph nodes (any N). It has not spread to distant sites (M0).

OR

Any T, N3, M0: The tumor is any size and may or may not have invaded nearby soft tissues or other structures (any T). The cancer has spread to at least 1 lymph node that is larger than 6 cm across (N3). It has not spread to distant sites (M0).

Stage IVC: Any T, Any N, M1: The tumor is any size and may or may not have invaded nearby soft tissues or other structures (any T). The cancer may or may not have spread to nearby lymph nodes (any N). It has spread to distant sites (M1).

If you have any questions about the stage of your cancer or how it affects your treatment, be sure to ask your cancer care team.

Survival rates for salivary gland cancer by stage

Survival rates are a way for doctors to discuss and compare the prognosis (outlook) for patients, based on the stage of the cancer or other traits. The numbers below are relative survival rates calculated from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, based on people who were diagnosed with salivary gland cancer between 1988 and 2001. There are some important points to note about these numbers:

• The survival rate refers to the percentage of patients who live at least a certain number of years after being diagnosed. Many patients live much longer than this.

• Relative survival rates (such as the numbers below) compare the observed survival rate with that expected for people without salivary gland cancer. This means that relative survival rates only refer to deaths from the cancer in question. They are considered to be a more accurate way to describe the outlook for patients with a particular type and stage of cancer.

• These numbers were derived from patients treated at least several years ago. These are some of the most current numbers we have available, but improvements in treatment since then mean that the survival rates for people now being diagnosed with these cancers may be higher.

• Survival statistics can sometimes be useful as a general guide, but they may not accurately represent any one person's prognosis. A number of other factors, including other tumor characteristics and a person's age and general health, can also affect outlook. Your doctor is likely to be a good source as to whether these numbers may apply to you, as he or she is familiar with the aspects of your particular situation.

As mentioned above, the stage is not the only factor that affects survival rates. Other factors, such as the grade of the cancer (how the cancer cells look under the microscope) and the type of salivary gland cancer are also important. For more information on the grades and types of salivary gland cancer, see the section "What is salivary gland cancer?"

Last Medical Review: 02/10/2009
Last Revised: 02/10/2009