Hypopharyngeal Throat Cancer Staging

What is hypopharyngeal cancer staging?

After a hypopharyngeal cancer diagnosis, oncologists proceed to ‘stage’ the tumor with the help of imaging scans (CT Scan), endoscopy tests, blood tests, etc. They can classify the tumor across various categories on the basis of its spread. If the tumor is confined to the primary site of origin, then it is referred to as localized (early stage) disease. If it has spread to a nearby site, or if there is any lymph node involvement, then it is termed as locally advanced, and if cancer has spread to other distant organs in the body, then it is labelled as a metastatic disease. This entire process is called staging.

Read more on what is throat cancer here.

Hypopharyngeal cancer staging explained with an image of hypopharynx anatomy

What information is provided by the staging of hypopharyngeal cancer?

The stage of hypopharyngeal cancer provides information on how aggressively cancer has spread within a patient’s body and is extremely helpful in determining the best course of action for a patient who has been diagnosed at a specific stage of the disease.

The stage of hypopharyngeal cancer is also useful in determining the probable outcomes and projected survival rate of a particular patient.

The earliest stage of hypopharyngeal throat cancer (stage 0) is called carcinoma in situ (CIS). Apart from stage 0, there are stages 1 to 4 for this type of cancer. The lower the staging number, the lesser aggressive cancer. A higher number (such as stage 4) indicates that cancer has spread further into the body.

How is hypopharyngeal throat cancer staged?

Hypopharyngeal cancer staging is dependent on the TNM system, developed by the American Joint Committee on Cancer (AJCC – 8th edition). TNM staging principles are based on the following three factors:

  • T – This represents the size of the main tumor, and indicates how far the tumor has grown inside the hypopharynx and in nearby tissue areas.
  • N – This represents the spread of cancer into nearby lymph nodes, and determines the number and size of the affected lymph nodes.
  • M – This represents the status of metastasis (spread) to distant organs in the body (commonly: the lungs, liver or bones)

Once the T, N and M aspects of the disease have been established via the right diagnostic systems, the information is consolidated to form a group stage of hypopharyngeal cancer that a specific patient exhibits. This is called the clinical stage of the disease.

What are the different stages of hypopharyngeal throat cancer?

Stage 0

(Tis | N0 | M0)

In stage 0 hypopharyngeal cancer:

  • The tumor is limited to the top layer of cellular lining of the hypopharynx. The tumor has not grown any deeper inside the throat (Tis).
  • The cancer has not spread to any of the nearby lymph nodes (N0).
  • The cancer has not metastasized to distant organs in the body (M0).

Stage 1

(T1 | N0 | M0)

In stage 1 hypopharyngeal cancer:

  • The tumor has grown in size and grown deeper. The tumor is still limited to one part of the hypopharynx. The tumor is not larger than 2 cms in size (T1).
  • The cancer has not spread to any of the nearby lymph nodes (N0).
  • The cancer has not metastasized to distant organs in the body (M0).

Stage 2

(T2 | N0 | M0)

In stage 2 hypopharyngeal cancer:

  • The tumor has grown beyond one part of the hypopharynx. It has either invaded a nearby area, or cms in size and lesser than 4 cms in size. The tumor has not affected the vocal cords (T2).
  • The cancer has not spread to any of the nearby lymph nodes (N0).
  • The cancer has not metastasized to distant organs in the body (M0).

Stage 3

(T3 | N0 | M0) or (T1 to T3 | N1 | M0)

In stage 3 hypopharyngeal cancer:

  • The tumor is larger than 4 cms in size, and has possibly spread to the food pipe. Alternatively, the tumor is constricting the vocal cords (T3).
  • The cancer has not spread to any of the nearby lymph nodes (N0).
  • The cancer has not metastasized to distant organs in the body (M0).

Alternate scenario for stage 3:

  • The tumor is of any size (small to large) and may not have extended to multiple parts of the hypopharynx. The tumor might not have affected the vocal cords either (T1 to T3).
  • The cancer has affected one lymph node (present on the same side of the neck as the tumor). This lymph node is less than 3 cms in size(N1).
  • The cancer has not metastasized to distant organs in the body (M0).

Stage 4 (advanced hypopharyngeal cancer)

(T1 to T4b | N0 to N3 | M0 to M1)

In stage 4 of hypopharyngeal throat cancer:

  • The tumor may have grown into the thyroid or cricoid cartilage, the hyoid bone, the thyroid gland, or into nearby muscle tissue or fat deposits. This is also called ‘moderately advanced local disease’. The size of the tumor is variable, and it may or may not have invaded the vocal cords (T1 to T4a). In cases of an extremely advanced local disease, the tumor has started growing into the area in front of the spine (in the neck). The tumor may have surrounded a carotid artery, or it may have spread to the lungs (T4b).
  • It is possible that the lymph nodes are not affected (N0), or a single node less than 3 cms in size may have been affected (N1). In moderately advanced local disease scenarios, a 3 to 6 cm long lymph node on the same side as the tumor might be affected (N2), and in cases of an extremely advanced local disease, more than one lymph node, larger than 6 cms in size may get affected (N3).
  • It is possible that the extent of the disease remains local (moderately advanced or extremely advanced local disease – M0), or that cancer has started spreading to other organs in the body (M1).

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