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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.
T1a: The tumor is limited to 1 vocal
cord.
T1b: The tumor is on both vocal cords.
T2: The tumor is growing into the supraglottis
and/or subglottis, and/or the vocal cords move only a little.
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.
Stage 0: Tis, N0, M0
Stage I: T1, N0, M0
Stage II: T2, N0, M0
Stage III: T1,2 or 3, N1, M0 or T3, N0, M0
Stage IVA: T1, 2 or 3, N2, M0, or
T4a, N0, 1 or 2, M0
Stage IVB: T4b, Any N, M0, or
Any T, N3, M0
Stage IVC: Any T, Any N, M1
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.
Last Revised: 05/14/2007
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