Nasopharyngeal Cancer

+ -Text Size

Early Detection, Diagnosis, and Staging TOPICS

How is nasopharyngeal cancer staged?

The stage of a cancer is a description of how far it has spread. The stage of nasopharyngeal cancer (NPC) is one of the most important factors in selecting treatment options and estimating a patient's outlook for recovery and survival (prognosis).

The stage of NPC is determined by the results of the physical exam, imaging tests (CT or MRI scan, etc.) and other tests, which are described in the section “How is nasopharyngeal cancer diagnosed?”, and by the results of surgery if it has been done.

If you have NPC, ask your cancer care team to explain the stage in a way you can understand. By knowing all you can about the stage of your cancer, you can take a more active role in making informed decisions about your treatment.

The American Joint Committee on Cancer (AJCC) TNM system

A staging system is a standard way for the cancer care team to sum up the extent of a cancer’s spread. The most common system used to describe the spread of NPC is the TNM system created by the American Joint Committee on Cancer (AJCC). This system contains 3 key pieces of information:

  • T describes whether the main (primary) tumor has invaded other organs or tissues near the nasopharynx.
  • N describes whether the cancer has spread to nearby (regional) lymph nodes (bean-sized collections of immune system cells throughout the body).
  • M indicates whether the cancer has metastasized (spread) to other parts of the body. (The most common sites of distant NPC spread are the lungs, liver, and bones.)

The numbers or letters that appear after T, N, and M provide more details about each of these factors:

  • The numbers 0 through 4 indicate further spread.
  • The letter X means “cannot be assessed” because the information is not available.
  • The letters “is” after the T stand for “in situ,” which means the tumor is still only in the layer of cells where it started and has not yet invaded deeper.

T groups for nasopharyngeal cancer

TX: Primary tumor cannot be assessed because of incomplete information.

T0: No evidence of a primary tumor.

Tis: Carcinoma in situ (cancer cells are found only in the surface layer of the nasopharynx but have not invaded into deeper layers).

T1: Tumor is in the nasopharynx. The cancer may also have grown into the oropharynx (the part of the throat in the back of the mouth) and/or nasal cavity but no farther.

T2: The cancer has grown into the tissues of left or right sides of the upper part of the throat (but not into bone).

T3: The tumor has grown into the sinuses and/or the bones nearby.

T4: The tumor has grown into the skull and/or cranial nerves (nerves in the head that lie near the nasopharynx and have special functions such as vision, smell, and eye movement), the hypopharynx (lower part of the throat), or the eye or its nearby tissues.

N groups for nasopharyngeal cancer

NX: Nearby lymph nodes cannot be assessed due to incomplete information.

N0: No spread to nearby lymph nodes.

N1: Spread to 1 or more lymph nodes on one side of the neck; OR spread to lymph nodes behind the throat (called retropharyngeal lymph nodes) on either side of the neck. In either case, no lymph node is larger than 6 cm (about 2½ inches) across.

N2: Spread to lymph nodes on both sides of the neck, none larger than 6 cm across.

N3: Spread to lymph nodes that are either:

  • N3a: larger than 6 cm across
  • N3b: located in the shoulder area just above the collarbone (this area is called the supraclavicular fossa)

M groups for nasopharyngeal cancer

M0: The cancer has not spread to tissues or organs far away from the nasopharynx.

M1: The cancer has spread to tissues or organs far away from the nasopharynx.

TNM stage grouping

Once the T, N, and M categories have been determined, this information is combined in a process called stage grouping. The stage is expressed as the number 0 (zero) or the Roman numerals I to IV (1-4). Some stages are subdivided with letters.

Stage 0: Tis, N0, M0: The cancer is “in situ.” Cancer cells are only in the surface layer of the nasopharynx but have not yet grown into deeper layers (Tis). The cancer has not spread to nearby lymph nodes (N0) or distant sites (M0).

Stage I: T1, N0, M0: The tumor is in the nasopharynx and may have spread to soft tissues of the nasal cavity and/or the oropharynx (T1). It has not spread to nearby lymph nodes (N0) or distant sites (M0).

Stage II: Either:

T2, N0, M0: The tumor has grown into the tissues of the left or right sides of the upper part of the throat (T2). It has not spread to nearby lymph nodes (N0) or distant sites (M0).

OR

T1 or T2, N1, M0: The tumor may still be confined to the nasopharynx, or it may have extended to the soft tissues of the nasal cavity or the oropharynx (T1), or the left or right sides of the upper part of the throat (T2). It has spread to one or more nearby lymph nodes, none of which is larger than 6 cm (about 2½ inches) across. These lymph nodes are either neck lymph nodes on one side or lymph nodes behind the throat (retropharyngeal lymph nodes) on either side (N1). The cancer has not spread to distant sites (M0).

Stage III: Either:

T3, N0 to N2, M0: The tumor has spread to the sinuses or the bones near the nasopharynx (T3). It may or may not have spread to lymph nodes in the neck or behind the throat, but none of these lymph nodes is larger than 6 cm across (N0 to N2). It has not spread to distant sites (M0).

OR

T1 or T2, N2, M0: The tumor may still be confined to the nasopharynx, or it may have grown into the soft tissues of the nasal cavity or the oropharynx (T1), or the left or right sides of the upper part of the throat (T2). The tumor has spread into nearby neck lymph nodes on both sides, with none of the lymph nodes larger than 6 cm across (N2). The cancer has not spread to distant sites. (M0).

Stage IVA: T4, N0 to N2, M0: The tumor has grown into the skull and/or cranial nerves, the hypopharynx (lower part of the throat), the eye, or its nearby tissues (T4). It may or may not have spread to nearby lymph nodes in the neck, none of which is larger than 6 cm across (N0 to N2). It has not spread to distant sites (M0).

Stage IVB: Any T, N3, M0: The tumor may or may not have extended into nearby soft tissues or bones (any T). It has spread to lymph nodes that are larger than 6 cm across and/or are located in the shoulder area above the collarbone (N3). The cancer has not spread to distant sites (M0).

Stage IVC: Any T, any N, M1: The tumor may or may not have extended into nearby soft tissues or bones (any T). It may or may not have spread to nearby lymph nodes (any N). It has spread to distant sites (M1).


Last Medical Review: 09/23/2013
Last Revised: 09/23/2013