ON THIS PAGE: You will learn about how doctors describe a cancer’s growth or spread. This is called the stage. To see other pages, use the menu.
Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting other parts of the body. Doctors use diagnostic tests to find out the cancer’s stage, so staging may not be complete until all of the tests are finished.
Knowing the stage helps the doctor decide what kind of treatment to recommend and can help predict a patient’s prognosis, which is the chance of recovery. There are different stage descriptions for different types of cancer.
TNM staging system
One tool that doctors use to describe the stage is the TNM system. Doctors use the results from diagnostic tests and scans to answer these questions:
Tumor (T): How large is the primary tumor? Where is it located?
Node (N): Has the tumor spread to the lymph nodes? If so, where and how many?
Metastasis (M): Has the cancer metastasized to other parts of the body? If so, where and how much?
The results are combined to determine the stage of cancer for each person. There are 5 stages of NPC: stage 0 (zero) and stages I through IV (1 through 4). The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments.
Here are more details of each part of the TNM system for NPC.
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 also 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.
Tis: This describes a stage called carcinoma (cancer) in situ. This is a very early cancer where cancer cells are found only in 1 layer of tissue.
T1: The tumor has not spread beyond the nasopharynx.
T2: The tumor extends into the soft tissue of the middle throat.
T3: The tumor extends into bony structure or into the area behind the nose.
T4: The tumor extends inside the head to an area of the brain or into the lower part of the throat.
The “N” in the TNM staging system is for lymph nodes. These tiny, bean-shaped organs help fight infection. Lymph nodes near where the cancer started are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes.
For people with NPC, doctors examine lymph nodes in a triangle-shaped area formed by 3 points: where the neck meets the shoulder, where the collarbone joins the tip of the shoulder, and where the front half of the collarbone meets the base of the neck.
NX: The regional lymph nodes cannot be evaluated.
N0 (N plus zero): There is no evidence of cancer in the regional lymph nodes.
N1: Cancer has spread to lymph nodes above the triangular area described above. The lymph nodes are on the same side of the neck as the primary tumor. The cancer found in the lymph nodes is 6 centimeters (cm) or smaller.
N2: Cancer has spread to lymph nodes on both sides of the neck, above the triangular area, but the cancer is 6 cm or smaller.
N3: Cancer found in lymph nodes is larger than 6 cm or is found in lymph nodes located in the triangle.
N3a: Cancer found in the lymph nodes is larger than 6 cm.
N3b: Cancer has extended to the triangle region.
The "M" in the TNM system indicates whether the cancer has spread to other parts of the body, called distant metastasis.
MX: Distant metastasis cannot be evaluated.
M0 (M plus zero): Cancer has not spread to other parts of the body.
M1: 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 0: A carcinoma in situ (Tis) with no spread to lymph nodes (N0) or distant metastasis (M0).
Stage I: A small tumor (T1) with no spread to lymph nodes (N0) and no distant metastasis (M0).
Stage IIA: A tumor that has extended beyond the nasopharynx (T2) but has not spread to lymph nodes (N0) or to distant parts of the body (M0).
Stage IIB: A tumor (T1 or T2) that has spread to lymph nodes (N1) but has not metastasized (M0).
Stage III: A noninvasive or invasive tumor (T1 or T2) that has spread to lymph nodes (N1 or N2) but has not metastasized (M0). This stage may also describe a larger tumor (T3) with or without lymph node involvement (N0, N1, or N2) and no metastasis (M0).
Stage IVA: This describes any invasive tumor (T4) with either no lymph node involvement (N0) or spread to only a single same-sided lymph node (N1) but no metastasis (M0). It is also used for any cancer (any T) with more significant lymph node involvement (N2) but no metastasis (M0).
Stage IVB: This describes any tumor (any T) with extensive lymph node involvement (N3a or N3b) but no metastasis (M0).
Stage IVC: This describes any tumor (any T, any N) when there is evidence of distant spread (M1).
Recurrent: If the cancer does return, there will be another round of tests to learn about the extent of the recurrence. These tests and scans are often similar to those done at the time of the original diagnosis.
Used with permission of the AJCC, Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition, published by Springer-Verlag New York, www.cancerstaging.org.
Information about the cancer’s stage will help the doctor recommend a specific treatment plan. The next section in this guide is Treatment Options. Or, use the menu to choose another section to continue reading this guide.