Nasopharyngeal Cancer Stages
After someone is diagnosed with nasopharyngeal cancer (NPC), doctors will try to figure out if it has spread, and if so, how far. This process is called staging. The stage of a cancer describes how much cancer is in the body. It helps determine how serious the cancer is and how best to treat it. Doctors also use a cancer's stage when talking about survival statistics.
The earliest stage of NPC is stage 0, also known as carcinoma in situ (CIS). The other stages range from I (1) through IV (4). Some stages are further divided, using A, B, etc. As a rule, the lower the number, the less the cancer has spread. A higher number, such as stage IV, means cancer has spread more. And within a stage, an earlier letter means a lower stage. Although each person’s cancer experience is unique, cancers with similar stages tend to have a similar outlook and are often treated in much the same way.
How is the stage determined?
The staging system most often used for NPC is the American Joint Committee on Cancer (AJCC) TNM system, which is based on 3 key pieces of information:
- The extent of the main tumor (T): How far has the tumor grown into nearby structures?
- The spread to nearby lymph nodes (N): Has the cancer spread to nearby lymph nodes in the neck? If so, how large are they and are they on the same side (left or right) as where the cancer started, or both sides of the neck?
- The spread (metastasis) to distant sites (M): Has the cancer spread to distant parts of the body? The most common sites of spread are the bones, lungs, liver, or lymph nodes in distant parts of the body.
These categories are mainly based on the results of any exams, biopsies, and imaging tests that have been done (described in How Is Nasopharyngeal Cancer Diagnosed?). Numbers or letters after T, N, and M provide more details about each of these factors.
Once the T, N, and M categories of the cancer have been determined, this information is combined in a process called stage grouping to assign an overall stage. For more on this, see Cancer Staging.
Nasopharyngeal cancer is typically given a clinical stage based on the results of any exams, biopsies, and imaging tests that might have been done (as described in Tests for Nasopharyngeal Cancers). If surgery has been done, the pathologic stage (also called the surgical stage) can be determined.
The system described below is the most recent AJCC system for NPC, effective January 2018.
NPC staging can be complex. If you have questions about your cancer's stage and what it might mean for you, ask your doctor to explain it to you in a way you understand.
Stages of nasopharyngeal cancer
AJCC stage |
Stage grouping |
Stage description* 6 centimeters (cm) = About 2½ inches |
0 |
Tis |
The tumor is only in the top layer of cells lining the inside of the nasopharynx, and has not grown any deeper (Tis). The cancer has not spread to nearby lymph nodes (N0) nor to distant parts of the body (M0). |
I |
T1 |
The tumor is in the nasopharynx. It might also have grown into the oropharynx (the part of the throat in the back of the mouth) and/or nasal cavity but no farther (T1). The cancer has not spread to nearby lymph nodes (N0) nor to distant parts of the body (M0). |
II |
T1 (or T0) |
The tumor is in the nasopharynx. It might also have grown into the oropharynx (the part of the throat behind the mouth) and/or nasal cavity but no farther (T1). OR No tumor is seen in the nasopharynx, but cancer is found in lymph nodes in the neck and is positive for Epstein-Barr virus (EBV) DNA, which makes it very likely to be NPC (T0). The cancer has spread to 1 or more lymph nodes on one side of the neck, or it has spread to lymph nodes behind the throat. In either case, no lymph node is larger than 6 cm across (N1). The cancer has not spread to distant parts of the body (M0). |
OR |
||
T2 |
The tumor has grown into the tissues of the left or right sides of the upper part of the throat, but not into bone (T2). The cancer has not spread to nearby lymph nodes (N0). OR, it has spread to 1 or more lymph nodes on one side of the neck, or it has spread to lymph nodes behind the throat. In either case, no lymph node is larger than 6 cm across (N1). The cancer has not spread to distant parts of the body (M0). |
|
III |
T1 (or T0) |
The tumor is in the nasopharynx. It might also have grown into the oropharynx (the part of the throat behind the mouth) and/or nasal cavity but no farther (T1). OR No tumor is seen in the nasopharynx, but cancer is found in lymph nodes in the neck and is positive for Epstein-Barr virus (EBV) DNA, which makes it very likely to be NPC (T0). The cancer has spread to lymph nodes on both sides of the neck, none of which is larger than 6 cm across (N2). The cancer has not spread to distant parts of the body (M0). |
OR |
||
T2 |
The tumor has grown into the tissues of the left or right sides of the upper part of the throat, but not into bone (T2). The cancer has spread to lymph nodes on both sides of the neck, none of which is larger than 6 cm across (N2). The cancer has not spread to distant parts of the body (M0). |
|
OR |
||
T3 |
The tumor has grown into the sinuses and/or the bones nearby (T3). The cancer might or might not have spread to nearby lymph nodes in the neck or behind the throat, but none are larger than 6 cm across (N0 to N2). The cancer has not spread to distant parts of the body (M0). |
|
IVA |
T4 |
The tumor has grown into the skull and/or cranial nerves, the hypopharynx (lower part of the throat), the main salivary gland, or the eye or its nearby tissues (T4). The cancer might or might not have spread to nearby lymph nodes in the neck or behind the throat, but none are larger than 6 cm across (N0 to N2). The cancer has not spread to distant parts of the body (M0). |
OR |
||
Any T |
The tumor might or might not have grown into structures outside the nasopharynx (any T). The cancer has spread to lymph nodes that are either larger than 6 cm across, or located in the shoulder area just above the collarbone (N3). The cancer has not spread to distant parts of the body (M0). |
|
IVB |
Any T |
The tumor might or might not have grown into structures outside the nasopharynx (any T). The cancer might or might not have spread to nearby lymph nodes (any N). The cancer has spread to distant parts of the body (M1). |
*The following additional categories are not listed in the table above:
- TX: Main tumor cannot be assessed due to lack of information.
- NX: Nearby lymph nodes cannot be assessed due to lack of information.
- Written by
- References
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
American Joint Committee on Cancer. Nasopharynx. In: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer; 2017: 103-111.
Last Revised: August 1, 2022
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