Staging Hypopharyngeal Cancer | Georgia Radiation Therapy

hypopharyngeal-staging

Once cancer has been confirmed, and tests are completed to determine if it’s spread outside of the primary area, a stage is given. This gives an indication of how large the tumor is, how quickly it’s growing and whether it has moved beyond the hypopharynx.

For hypopharyngeal cancer, the TNM system created by the American Joint Committee on Cancer (AJCC) is most commonly used by doctors for staging. The TNM system is based on 3 key pieces of information:

How big the main tumor (T) is
If the cancer has spread to nearby lymph nodes (N)
The spread (metastasis) to distant parts of the body (M)

Numbers or letters after T, N, and M provide more details about each of these factors. Lower numbers mean that the cancer is in an early stage. Higher numbers mean the cancer is more advanced.

Tumor (T)

TX: The primary tumor cannot be evaluated.
Tis: This is a stage called carcinoma (cancer) in situ. It is a very early cancer where cancer cells are found in only 1 layer of tissue.
T1: The tumor is 2 cm or smaller and is limited to a single place in the lower throat.
T2: The tumor involves more than 1 site in the lower throat, or the tumor measures between 2 cm and 4 cm but does not touch the voice box.
T3: The tumor is larger than 4 cm or has spread to the larynx or esophagus.
T4a: The tumor has spread into nearby structures, such as the thyroid gland, the arteries that carry blood to the brain, or the esophagus.
T4b: The tumor has spread to the prevertebral fascia (space in front of the spinal cord), encases the arteries, or involves the chest area.

Node (N)

When cancer has spread through a lymph node and into the tissues directly surrounding it, it is referred to as extranodal extension (ENE). Knowing whether ENE is present plays an important role in the evaluation of lymph nodes in hypopharyngeal cancer.

Evaluation of nodes can be clinical (based on the results of tests done before surgery) or pathological (based on what is found during surgery plus the results of physical examinations, imaging scans, and biopsies).

Clinical N

NX: The regional lymph nodes cannot be evaluated.
N0 (N plus zero): There is no evidence of cancer in the regional lymph nodes.
N1: The cancer has spread to a single lymph node on the same side as the primary tumor, and the cancer found in the node is 3 cm or smaller. There is no ENE.
N2a: 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. There is no ENE.
N2b: Cancer has spread to more than 1 lymph node on the same side as the primary tumor, and none measures larger than 6 cm. There is no ENE.
N2c: Cancer has spread to more than 1 lymph node on either side of the body, and none measures larger than 6 cm. There is no ENE.
N3a: The cancer is found in a lymph node and is larger than 6 cm. There is no ENE.
N3b: There is ENE in any lymph node.

Pathological N

NX: The regional lymph nodes cannot be evaluated.
N0 (N plus zero): There is no evidence of cancer in the regional lymph nodes.
N1: The cancer has spread to a single lymph node on the same side as the primary tumor, and the cancer found in the node is 3 cm or smaller. There is no ENE.
N2a: Cancer has spread to 1 lymph node and is 3 cm or smaller, but there is ENE. Or, 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, and there is no ENE.
N2b: Cancer has spread to more than 1 lymph node on the same side as the primary tumor, and none measures larger than 6 cm. There is no ENE.
N2c: Cancer has spread to more than 1 lymph node on either side of the body, and none measures larger than 6 cm. There is no ENE.
N3a: The cancer is found in a lymph node and is larger than 6 cm. There is no ENE.
N3b: There is ENE in a single lymph node on the same side as the primary tumor, and it is larger than 3 cm. Or, cancer has spread to many lymph nodes, and at least 1 has ENE. Or, there is ENE in a single lymph node on the opposite side of the primary tumor that is 3 cm or smaller.

Metastasis (M)

M0: The cancer has not spread to other parts of the body.
M1: The cancer has spread to other parts of the body.

Hypopharyngeal Cancer Stage Grouping

Doctors assign the stage of hypopharyngeal cancer by combining the T, N, and M classifications. The standardized stages of hypopharyngeal cancer are:

Stage 0: abnormal cells in the top layer of cells lining of the hypopharynx that may become cancer (Tis, N0, M0)
Stage I: cancer is only in one part of the hypopharynx and is 2 centimeters or smaller (T1, N0, M0)
Stage II: the tumor is between 2 and 4 centimeters and has grown into more than one part of the hypopharynx, or it has grown into a nearby area; it has not spread to nearby lymph nodes or to distant parts of the body (T2, N0, M0)
Stage III:
- The tumor is larger than 4 cm or has spread to the epiglottis, but the cancer has not spread to lymph nodes or other parts of the body (T3, N0, M0).
  OR
- The tumor has not invaded nearby tissues except the epiglottis. Cancer is in 1 lymph node on the same side as the primary tumor, and it is 3 cm or smaller, with no ENE. Cancer has not spread to other parts of the body (T1–T3, N1, M0).

Stage IVA:
- The tumor has invaded the larynx, muscle of the tongue, muscles in the jaw, the roof of the mouth, or jawbone. Cancer may have spread to 1 lymph node, but it has not spread to other parts of the body (T4a, N0 or N1, M0).
  OR
- The tumor may be small or it may have invaded nearby structures, like the larynx, muscles of the tongue or jaw, the roof of the mouth, or jawbone. Cancer has spread to 1 or more lymph nodes, but none is larger than 6 cm. There is no ENE. Cancer has not spread to other parts of the body (T1–T4a, N2, M0).

Stage IVB:
- The tumor is any size. The cancer is found in a lymph node and is larger than 6 cm, but there is no ENE, or there is ENE in any lymph node. Cancer has not spread to other parts of the body (any T, N3, M0).
  OR
- The tumor has invaded muscles and bones in the region of the mouth; the nasopharynx, which is the air passageway at the upper part of the throat behind the nose; or the base of the skull, or the tumor encases the carotid artery. Lymph nodes may or may not be involved. Cancer has not spread to other parts of the body (T4b, any N, M0).

Stage IVC: any size tumor has spread to other parts of the body (any T, any N, M1)

Grade (G)

Doctors also categorize this type of cancer by its grade (G). The grade describes how much cancer cells look like healthy cells when viewed under a microscope.

GX: The grade cannot be evaluated.
G1: The cells look more like normal tissue (well-differentiated).
G2: The cells are moderately differentiated.
G3: The cells don’t resemble healthy tissue (poorly differentiated).
G4 (hypopharynx only):
The cells don’t look like healthy tissue at all (undifferentiated).