Staging is the process of finding out how far a cancer has spread. The extent of spread of laryngeal or hypopharyngeal cancer is the most important factor in selecting treatment options and estimating the course of a patient's illness and their outlook for recovery and survival (prognosis). A staging system is a way for members of the cancer care team to summarize the extent of a cancer's spread.

If you have laryngeal or hypopharyngeal cancer, ask your cancer care team to explain the staging of your cancer in a way that you understand. Knowing all you can about staging lets you take a more active role in making informed decisions about your treatment.

The American Joint Committee on Cancer (AJCC) TNM System

The most common system used to describe the stages of cancers is the American Joint Committee on Cancer (AJCC) TNM system.

• T stands for tumor (its size and how far it has spread within the larynx and hypopharynx and to nearby organs). 
• N stands for spread to lymph nodes (bean-sized collections of immune system cells that help fight infections and cancers). 
• M is for metastasis (spread to distant organs).

Using the TNM staging system, information about the tumor, lymph nodes, and metastasis is combined to assign a stage. This process is called stage grouping. The stage is described in Roman numerals from I to IV. Patients with lower stage cancers have a better prognosis for a cure or long-term survival.

The T stage of cancers of the larynx and hypopharynx depends on how far it has spread to the surrounding tissues from its origin. Spread may be evaluated by indirect examinations using mirrors, by direct endoscopy using scopes, and, if your doctor can reach it, by feeling the texture of the area.

Watching movement of the vocal cords with special mirrors while the patient makes certain sounds can tell the doctors about the extent of local spread. If your vocal cords move normally, it is unlikely that the cancer has affected deeper tissues. Vocal cord fixation (lack of movement) suggests involvement by cancer. Imaging studies such as CT or MRI scans may be used to add more detailed information.

T staging of laryngeal and hypopharyngeal cancers describes spread of the cancer precisely in relation to specific areas of the larynx, hypopharynx, and the surrounding structures. These areas are shown in an illustration in the section, "What Are Laryngeal and Hypopharyngeal Cancers?" Higher T stage numbers indicate more spread within the larynx or hypopharynx and to other nearby areas in the neck.

The features used to assign the T stage of laryngeal cancer vary according to the area of the larynx involved -- supraglottis, glottis, or subglottis. T staging for hypopharyngeal cancer differs from T staging for cancer of the larynx.

You may want to talk to your doctor about the stage of your cancer. It will be important that the doctor illustrate it using a diagram of the larynx.

T Stages Common to All Laryngeal and Hypopharyngeal Cancers

TX: Cannot be staged (information not available)

T0: No evidence of tumor

Tis: Carcinoma in situ. The cancer cells are limited to the epithelium, and there is no growth into the connective tissue of the larynx or hypopharynx. (Very few hypopharyngeal and larynx cancers are found at this early stage.)

T Stages of Supraglottic Cancer

The T stage of cancer of the supraglottis is based on how many subsites (different parts of the larynx) are involved and how far outside the larynx the cancer has spread. The 5 subsites of the supraglottic part of the larynx are the ventricular bands (also called false vocal cords), arytenoids, suprahyoid epiglottis, infrahyoid epiglottis, and aryteno-epiglottic folds.

T1: The tumor is limited to 1 subsite of the supraglottis, and the vocal cords move normally.

T2: The tumor invades more than 1 subsite of the supraglottis; the vocal cords move normally.

T3: The tumor is limited to the larynx, and the vocal cords do not move and/or invasion of the postcricoid area, paraglottic space, or pre-epiglottic (in front of the epiglottis) tissues.

T4a: The tumor invades through thyroid cartilage (firm tissue that separates the thyroid gland from the front of the larynx) and/or extends to tissues beyond the larynx.

T4b: The tumor invades prevertebral (in front of the cervical spine) space, is growing around a carotid artery, or is growing down into the front of the chest cavity.

T Stages of Glottic Cancer

T1: The tumor is limited to the vocal cord(s); the vocal cords move normally.

T3: The tumor is limited to the larynx and the vocal cords don't move and/or the tumor invades the paraglottic space, and/or there is minor erosion of thyroid cartilage (firm tissue that separates the thyroid gland from the front of the larynx).

T4a: The tumor invades through thyroid cartilage and/or extends to tissues beyond the larynx.

T4b: The tumor invades prevertebral space (in front of the cervical spine), surrounds a carotid artery, or is growing down into the front of the chest cavity.

T Stages of Subglottic Cancer

T1: The tumor is limited to the subglottis.

T2: The tumor extends to the vocal cords, with normal or reduced vocal cord movement

T3: The tumor is limited to the larynx; the vocal cords donÂ’t move

T4a: The tumor invades through the cricoid or thyroid cartilage and/or extends to tissues beyond the larynx.

T4b: The tumor invades prevertebral space (in front of the cervical spine), surrounds a carotid artery, is growing down into the front of the chest cavity.

T Stages of Hypopharyngeal Cancer

Spread of cancer within the hypopharynx is described according to the size of the tumor and how many subsites (areas of the hypopharynx) are involved by the cancer. The 3 subsites of the hypopharynx are the pharyngo-esophageal junction, pyriform sinus, and posterior pharyngeal wall.

T1: The tumor is limited to 1 subsite of the hypopharynx and is smaller than 2 centimeters (cm) (about 3/4 of an inch) in diameter.

T2: The tumor involves more than 1 subsite of the hypopharynx or an adjacent site or is 2 to 4 cm in size, and doesn't affect the vocal cords.

T3: The tumor is larger than 4 cm in diameter or is affecting the vocal cords.

T4a: The tumor invades the cricoid or thyroid cartilage, hyoid bone, thyroid gland, esophagus, or the strap muscles in front of the larynx.

T4b: The tumor invades the space in front of the cervical spine, is growing around a carotid artery, or is growing down into the front of the chest cavity.

N (Regional Lymph Node) Stages of Laryngeal and Hypopharyngeal Cancers

The N staging is the same for laryngeal and hypopharyngeal cancers. The stages are as follows:

NX: The lymph nodes cannot be assessed (information not available).

N0: There is no evidence of spread to the lymph nodes.

N1: The cancer has spread to a single lymph node not larger than 3 cm (about 1¼ inch) in diameter. The lymph node is on the same side of the neck as the primary tumor.

N2a: There is spread in 1 lymph node between 3 cm and 6 cm, on the same side of the neck as the origin of the cancer.

N2b: There is spread in multiple lymph nodes, none larger than 6 cm, and all on the same side of the neck as the origin of the cancer.

N2c: There is spread to 1 or more lymph nodes on both sides of neck or on the side opposite the origin of the cancer. None can be larger than 6 cm.

N3: There is spread to 1 or more lymph nodes larger than 6 cm.

M (Distant Metastasis) Stages of Laryngeal and Hypopharyngeal Cancers

The M staging for all head and neck cancers, including laryngeal and hypopharyngeal cancers, is the same. The stages are as follows:

MX: Information not available. Unable to tell if distant metastasis is present.

M0: No distant metastasis. 

M1: Distant metastasis present.

Stage Grouping

Once the T, N, and M stages have been assigned, this information is combined (called stage grouping) to assign an overall stage of 0, I, II, III, or IV. Stage grouping rules are the same for all cancers of the hypopharynx and the supraglottic, glottic, and subglottic areas of the larynx.

Survival rates by stage: Below are listed the 5-year relative survival rates for cancers from each of the sites. These are data from the National Cancer Data Base, published in the AJCC staging manual (see the "References" section). The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Keep in mind that many of these patients live much longer than 5 years after diagnosis, and 5-year rates are used to produce a standard way of discussing prognosis.

Five-year relative survival rates exclude patients dying of other diseases from the calculations, and are considered to be a more accurate way to describe the prognosis for patients with a particular type and stage of cancer. Of course, 5-year rates are based on patients diagnosed and treated more than 5 years ago. Recently diagnosed patients with many types of cancer may have a more favorable outlook because of improvements in treatment.

Unfortunately, a recent study found that the average survival for patients cancer of the larynx has not improved during the past couple of decades (from 1974-1997) and the prognosis for hypopharyngeal cancer improved only slightly. Nonetheless, there has been some been very recent progress in treating these cancers, and there is hope that the outlook for patients diagnosed in the past few years will be better.

Supraglottis

Stage	5-year relative survival (percent)
I	83
II	70
III	57
IV	43

Glottis

Stage	5-year relative survival (percent)
I	65
II	62
III	55
IV	37

Subglottis

(These numbers are less accurate because of the small number of patients)

Stage	5-year relative survival (percent)
I	54
II	68
III	53
IV	36

Hypopharynx

Stage	5-year relative survival (percent)
I	41
II	36
III	36
IV	10

If you have any questions about the stage of your cancer or how it affects your treatment, do not hesitate to ask your doctor.