Cancer of Larynx
The larynx or
voice box is located in the neck. The large cartilage that forms
the front of the larynx produces a sharp bulge in the neck in men
and is called the ‘Adams apple’. It contains the vocal
cords and the muscles, which move them. The vocal cords vibrate
and make sound when air is directed against them. The sound echoes
through pharynx, mouth, nose and sinuses to make a person’s
voice. Air passes through the pharynx, then the larynx on the way
to the windpipe and lungs. The food passes through the pharynx to
the esophagus. The larynx has a leaf like structure called epiglottis,
which prevents the food going into the airway.
The
larynx include the:
- Vocal cords
(glottis)
- Area above
the vocal cords, including epiglottis (supraglottis), and
- Area below
the vocal cords (subglottis) that connects the larynx to the wind
pipe (trachea)
Like other parts
of the body, the larynx is made up of many types of cells. When
cells divide in an abnormal, uncontrolled way, they can form a non-cancerous
(benign) or cancerous (malignant) tumour. Approximately 95% of laryngeal
cancers are squamous cell cancers arising from the mucous membranes.
Cancers forming in the glands and connective tissues of the larynx
are rare. Cancers of the larynx is especially common in smokers.
It is typical for the cancers of the squamous cells of the larynx
to begin as pre-cancerous conditions, such as an abnormal growth
(dysplaisa). Not all pre-cancerous conditions develop into cancer.
They sometimes go away without treatment, especially if the person
stops smoking or eliminates other risk factors. Approximately 25%
of patients diagnosed with laryngeal cancers have another cancer
in a nearby area, such as mouth, oesophagus or lung. Another 15%
will later develop cancer in one of these areas. That’s why
patients should continue with follow-up examinations throughout
their lifetime.
Risk
factors:
1) Use of
tobacco products: This includes cigarettes and smokeless tobacco.
Smokers are 5 to 35 times more likely to develop laryngeal cancers
than non-smokers. Statistics show that 37 % of head and neck cancer
patients who continue smoking will develop a recurrent tumour
or second cancer. Compare that to only 6% of the head and neck
cancer recurrence in patients who stop smoking.
2) Excessive consumption of alcohol:
3) Occupational hazard: Over exposure to paint fumes, wood dust;
some chemicals and even asbestos may increase the risk of developing
laryngeal cancers.
Clinical
presentation:
An
ENT surgeon should be seen if any of the following symptoms
exist for more than two weeks. Pain is not an early symptom.
Symptoms of laryngeal cancer include:
- Hoarseness
of voice
- A lump
in the neck
- A sore
throat or ear ache
- Difficulty
in breathing
- Pain
and difficulty in swallowing
|
 |
Most of the
cancers of the larynx begin on the vocal cords (atleast 70%). These
tumours are seldom painful, but they almost always cause hoarseness.
Tumours that begin in the area below the vocal cords are rare. Such
tumours can make it hard to breathe. Breathing may even become noisy.
Early detection
of laryngeal cancer is important because treatment is most effective
before the disease has spread. These types of cancers usually spread
to lymph nodes in the neck, the back of the tongue, other parts
of the throat and neck and the lungs. Spread of cancer to lymph
nodes of patients with true cord cancer is extremely rare. The reverse
is true for patients with supraglottic cancers, where up to 40%
of patients will have some spread of cancer to the lymph nodes of
the neck.
The ENT surgeon
with the help of small mirrors or a fibreoptic endoscope will examine
the larynx. The fibreoptic flexible laryngoscopy can be done as
an out patient procedure under local anesthesia by passing a thin
endoscope through the nose in to the pharynx.
If something
suspicious is seen, then the next step is doing endoscopy under
general anesthesia. The larynx is examined with the help an operating
microscope (Microlaryngoscopy). If some area looks abnormal, then
biopsy is done from that area.
If neck nodes
are enlarged, fine needle aspiration is done for cytological examination
(FNAC) by the pathologist to rule out metastatic carcinoma. If cancer
is found, the doctor will need to know the extent of the disease.
This is called staging. In most cases, the most important factor
in considering treatment options is the stage of the disease. The
stage is based on the size of the tumour, as well as whether or
not the cancer has spread (metastasized) and where it has spread.
To obtain more information about the location and extent of the
cancer, the doctor may perform the following investigations.
- CT scan
of neck
- X-ray /
CT scan of chest
- Ultrasound
of liver
- MRI neck
Treatment options:
Treatment of small cancers of the larynx usually results in a good
outcome. The cure rate for such a cancer that has not spread is
75-95 percent. Radiation often is the first treatment option for
this type of cancer because this helps to preserve the voice. There
are numerous surgical procedures now available that result in just
partial removal of the voice box in order to retain normal breathing
patterns and speaking.
Surgery may
also be needed later if the cancer recurs. Advanced laryngeal cancer
may be treated with chemotherapy and radiation therapy in an effort
to avoid surgical removal of the larynx. Locally advanced lesions,
intermediate-sized cancers and recurrent cancers require different
treatment therapies altogether.
The treatment
plan should be individualized depending on the location of the cancer,
its size, the stage of the disease and the patient’s general
health.
Surgery:
Surgery for cancer if the larynx involves removal of the affected
portion of the larynx with significant normal healthy tissue around
it. Complete surgical clearance of the tumour is achieved with the
help of the pathologist who examines the removed tissue at the time
of surgery (Frozen section) and says whether removal was complete
or needs further removal.
- Patients
with laryngeal cancer may undergo one of these types of surgeries.
- Cordectomy
– removal of the vocal cord
- Supraglottis
laryngectomy- removal of the supraglottis
- Partial laryngectomy
– removal of part of the larynx
- Total laryngectomy
– removal of the entire larynx.
With a partial
laryngectomy, the surgeon creates a breathing hole in the neck.
This artificial opening (called a stoma) may be temporary. The stoma
is the hole through which air enters the trachea and lungs. Once
the stoma closes, they are able to breathe normally and speak. When
the tumour involves a large portion of the larynx, a more aggressive
surgery is done to remove entire voice box. This procedure is called
total laryngectomy. In order to complete this operation the windpipe
must be brought out to the neck to form a permanent opening called
stoma. Air can no longer pass from the lungs into the mouth and
nose. The inhaled air passes directly through the stoma into the
trachea and then into the lungs. The connection between the mouth
and oesophagus is usually not affected, so food and liquid can be
swallowed just as they were before the operation. As the vocal cords
were removed, a laryngectomee patient will no longer have laryngeal
speech. This does not mean that speech is lost and there are ways
to talk without a larynx.
Management of lymph nodes will be included in whatever treatment
plan is felt to be appropriate for the patient. This will involve
surgery or radiotherapy. Many times an operation called a neck dissection
is done to remove lymph nodes of the neck that may be involved with
cancer.
Alaryngeal
speech:
Even when the patient loses the voice box in total laryngectomy,
he/she can still learn to talk. There are basically 3 methods by
which patient can learn to talk.
1) Oesophageal
Speech: In this method, patient is taught to swallow the air and
then to belch out. When the air comes out, the junction of the
pharynx and food pipe acts like vocal cord and with the movement
of tongue, palate and lips, speech is produced. The voice will
be rough and monotonous. It requires lots of practice and perseverance
on the part of the patient. About 50 – 60% of patients develop
reasonable speech with this method. Patient has to periodically
break the speech to swallow air.
2) Electronic larynx: It is a hand held; electronic device, which
has a diaphragm at one end, that vibrates. This end of the device
is held over the floor of mouth and the patient start to articulate
the tongue and lip musculature. The sounds of these movements
are amplified by this device and speech is produced. The speech
sounds like robotic speech.
3) Voice Prosthesis: This device is a valve that is placed surgically
between the airway in the neck and the oesophagus (food pipe).
By covering the breathing hole (stoma) in the neck with a finger,
a patient is able to force air through the valve into the food
pipe (oesophagus) and out of the mouth. Relatively normal speech
is achievable. This valve can be inserted at the time of the cancer
surgery itself or later on if the patient does not develop oesophageal
speech.
|
