95% of cancers in the larynx and hypopharynx are
squamous cell carcinomas with laryngeal cancer being one of the
most common of the head and neck cancers. As with oropharyngeal
cancer, the two most important risk factors for cancer of the
larynx/hypopharynx are tobacco and alcohol use. Older men are
at greater risk, particularly if there has been occupational exposure
to dust, paint fumes or asbestos. Blacks are more likely to get
these types of cancer than whites, and some other risk factors
include:
- Poor nutrition (a diet low in Vit. A and E)
- Gastroesophageal reflux (GERD)
- Human papilloma virus exposure
- Plummer-Vinson Syndrome ( a rare condition of iron deficiency
and swallowing difficulties
Among the common symptoms of cancers in the larynx/hypopharynx
are:
- Hoarseness of the voice
- airway blockage
- persistent sore throat
- lump in the neck
- difficulty swallowing
- ear pain
- chronic bad breath
- noisy breathing
Those who experience any of these symptoms should bring them
to the doctor's attention. The general doctor's exam may be followed
by referral to the head and neck surgeon for further evaluation.
The head and neck surgeon will perform a thorough head and neck
exam that will include a form of endoscopy
known as laryngoscopy.If an "indirect" laryngoscopy
performed with a hand-held mirror is inconclusive or suggestive
of a problem, the surgeon will want to take a direct look into
the area. Under sedation or full anesthesia, a "direct"
laryngoscopy can be performed, allowing the surgeon a complete
view of the hypopharynx and upper larynx and the ability to sample
(biopsy) suspicious tissues. Many surgeons will advocate a "triple
endoscopy" so that they can evaluate the pharynx and larynx,
the subglottic larynx and trachea and the esophagus.
When a tumor is found, the surgeon will go on to stage the cancer
by use of xrays,
CT scan, MRI
scan, bone scan or PET
scan.
Staging
TNM is an abbreviation for tumor (T), node (N), and metastasis
(M). Doctors look at these three factors to determine the stage
of cancer.
T0: No evidence of a tumor is found.
Tis: a stage called "carcinoma in situ", a very early
cancer found only in the surface layer of tissue.
Glottis
T1: a tumor that is limited to the vocal cords and does not affect
cord movement .
T1a: a tumor in just the right or left vocal cord.
T1b: a tumor involving both vocal cords.
T2: a tumor that has spread to the supraglottis or subglottis.
or a tumor that affects cord movement.
T3: a tumor limited to the larynx and that affects the vocal cords.
T4a: a tumor that invades the thyroid cartilage or tissues beyond
the larynx.
T4b: a tumor that invades the chest and surrounds the arteries.
Supraglottis
T1: a tumor located in a single area above the cords that doesn't
affect cord movement.
T2: a tumor that started in this area, but that has spread to
the mucus membranes in other areas, (e.g. base of the tongue).
T3: a tumor that is limited to the larynx with vocal cord involvement
or has invaded surrounding tissues.
T4a: a tumor that invades the thyroid cartilage or tissues beyond
the larynx.
T4b: a tumor that invades the chest area and encases arteries.
Subglottis
T1: a tumor that is limited to the subglottis.
T2: a tumor that extends to the vocal cords and may or may not
affect cord movement.
T3: a tumor limited to the larynx that affects the vocal cords.
T4a: a tumor that invades cricoid or thyroid cartilage or invades
tissues beyond the larynx.
T4b: a tumor that invades the chest and encases the arteries.
Hypopharynx
T1: a small tumor (2 cm) that is limited to a single site in the
hypopharynx.
T2: a tumor that involves more than one site in the hypopharynx,
but does not touch the larynx, or a tumor that measures larger
than 2 cm but not larger than 4 cm.
T3: a tumor that is larger than 4 cm or one that extends to the
larynx.
T4a: a tumor that extends into the adjacent structures, such as
the thyroid, carotid vessels or the esophagus.
T4b: a tumor that invades the prevertebral fascia, encases the
arteries or involves the mediastinum.
The "N" in the TNM system stands for lymph nodes, the
small, bean-shaped organs that help fight infection.
N0: no evidence of cancer in the regional nodes.
N1: cancer has spread to a single node on the same side as the
tumor and the cancer in the node is 3 cm or smaller.
N2: any of these following:
N2a: cancer has spread to a single lymph node on the same side
as the tumor, is larger than 3 cm, but not larger than 6 cm.
N2b: cancer has spread to more than one node on the same side
as the tumor, but none measure larger than 6 cm.
N2c: cancer has spread to more than one lymph node on either side
of the neck, but none measure larger than 6 cm.
N3: cancer found in lymph nodes is larger than 6 cm.
The "M" in the TNM system describes cancer that has
spread to other parts of the body.
MX: distant metastasis cannot be evaluated.
M0: cancer has not spread to other parts of the body.
M1: cancer t has spread to other parts of the body.
Stages using TNM
Stage 0: carcinoma in situ (Tis), with no spread to lymph nodes
(N0) and no distant metastasis (M0).
Stage I: a small tumor (T1), with no spread to lymph nodes (N0)
and no distant metastasis (M0).
Stage II: a tumor with some regional extension (T2) that has
not spread to lymph nodes (N0) or to distant areas (M0).
Stage III: larger tumors (T3), with no spread to regional lymph
nodes (N0) or metastasis (M0), or smaller tumors (T1, T2) that
have spread to lymph nodes (N1), but show no sign of metastasis
(M0).
Stage IVA: any invasive tumor (T4a), with no lymph node involvement
(N0) or spread to only a single same-sided lymph node (N1), but
no metastasis (M0). Or, any cancer (T) with more significant nodal
involvement (N2), but no metastasis (M0).
Stage IVB: any cancer (T) with extensive nodal involvement (T3),
but no metastasis M0).
Stage IVC: evidence of distant spread (M1).
Besides staging a tumor, doctors also assess what is called its
"grade." Because normal tissues are made up of many
different types of cells grouped together, (something called "differentiation"),
tumors are examined microscopically to see if their cells show
relatively more or less differentiation. Tumors with less differentiation
are more aggressive.
GX: the grade cannot be determined
G1: the cells look more like normal tissue (well differentiated).
G2: the cells are moderately differentiated.
G3: the cells don't look like normal tissue at all (poorly differentiated).
Treatment
The treatment of laryngeal and hypopharyngeal cancer depends
on the size and location of the tumor, whether the cancer has
spread and the patient's overall health. Although curing the cancer
is the primary goal, preserving the function of affected organs
is also important. When doctors plan treatment, they consider
how it would likely affect a person's quality of life.
Surgery and radiation therapy are both important treatment methods
and, in some cases, chemotherapy has a role to play as well.
Surgery can in some cases employ the technique
of trans-oral
laser microsurgery. This method often allows the surgeon to
preserve more normal tissue, but its use is not yet widespread.
(A few surgeons like Dr. Caruana have been pioneering the use
of this method.)
Standard surgical treatments include partial and total laryngectomy:
Partial laryngectomy removes only
part of the larynx. It preserves the voice since only part of
the larynx is removed. The following are some different types
of partial laryngectomy:
- "Supraglottic laryngectomy" removes only the area
above the vocal cords. If part of the hypopharynx is removed
as well this is called a partial pharyngectomy.
- "Cordectomy" removes a vocal cord.
- "Vertical hemilaryngectomy" removes one side of
the larynx.
- "Supracricoid partial laryngectomy removes the vocal
cords and the areas around them.
Total laryngectomy removes the
entire larynx, permanently eliminating speech using the vocal
cords.Asa a part of this operation, a permanent opening in the
windpipe (
tracheostomy) is made to allow the patient to breathe.
Patients with larger tumors that involve both the larynx and
the hypopharynx may require "laryngopharyngectomy."
In this surgery, the entire larynx, together with part or all
of the hypopharynx is removed. Following this, procedures must
be done to reconstruct the pharynx, often using a microsurgically
transferred flap of skin or of small intestine.
If there is reason to suspect spread to local lymph nodes, some
form of "lymph node dissection" may be carried out.
The nature and extent of lymph node removal will vary from removal
of just a few nodes near the area of the tumor, to "radical
neck dissection" where nearly all neck nodes are removed.
Radiation therapy uses high-energy x-rays to
kill cancer cells.The radiation may come from a machine outside
the body ("external beam therapy") or from radioactive
materials that are put into the tissues through thin plastic tubes
or needles (internal radiation therapy, or "bachytherapy").
Radiation may be used as an adjunctive treatment with surgery,
or, in some cases, as the primary mode of therapy. Those who stop
smoking before radiation therapy have a better chance of surviving
longer.
It is important that the head and neck cancer patient who needs
radiation be prepared by an oncologic dentist.
(See
Dentistry in Head and Neck Cancer)
In some cases, local treatments (surgery and/or radiation) may
be supplemented by "systemic" treatment with chemotherapy.
Chemotherapy is administered by mouth or by injection,
introducing medicines that are able to travel throughout the body
and potentially destroy any cancer cells that "broke away"
and escaped the local treatment. When this therapy is given after
local treatment as a supplement, it is known as "adjuvant"
chemotherapy. Treatments given to shrink a tumor before local
surgery or radiation are used is called, "neo-adjuvant"
therapy. |
For
the discussion below, you may wish to refer to 
