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| Cancer of the nasopharynx |
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Written by Mr Kim W Ah-See, consultant otolaryngologist, head and neck surgeon
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The nasopharynx is the space within the skull that is above the
palate (roof of the mouth) and behind the nose. It communicates at the front
with the outside air, via the nostrils, and at the back with the cavity of the
mouth and throat (oropharynx).
What is cancer of the nasopharynx?
Cancer of the nasopharynx is rare in the UK, accounting for
less than 0.25 per cent of all cancers.
It occurs when the normal cells that line this area change into
malignant cancer cells. The type of cancer, or carcinoma, is classified
according to the type of cell that undergoes the malignant change. Of these
cancers, 90 per cent are of the squamous cell type. Other types are called
adenocarcinoma, adenoid cystic carcinoma and lymphoma.
What causes cancer of the nasopharynx?
While cancer of the nasopharynx is rare in the UK it is much
commoner in southern China where the people have a genetic susceptibility to
the disease. Even if these people emigrate to other countries they take this
higher risk with them, passing it on to their children who will have a higher
risk of developing the disease than the local non-Chinese population. Another
factor thought to be important in these Chinese patients is their high dietary
intake of salted fish.
A third risk factor is previous infection with the Epstein-Barr
virus, which is the virus responsible for
glandular fever.
Patients with cancer of the nasopharynx show high levels of
antibody to this virus in their blood, indicating previous infection. However,
the exact role of this virus in causing this disease remains unclear.
What are the symptoms of cancer of the nasopharynx?
Unfortunately, despite the nasopharynx being a small confined
area at the back of the nasal passages, patients often have advanced disease by
the time they are diagnosed. The symptoms also are quite non-specific and are
often put down to minor illnesses such as a 'cold'. The commonest
symptoms are:
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a blocked nose
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deafness (particularly in one ear only)
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a lump in the neck (a sign of spread of the cancer to the
glands in the neck).
Other less common symptoms are:
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headache
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problems with swallowing
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double vision
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nosebleeds.
The peak age group affected in Chinese patients is in the 30s
while in Caucasians it tends to occur in the 50s. Males are twice as likely as
females to get this disease.
How is cancer of the nasopharynx diagnosed?
Once a person presents with one or more of the above symptoms,
especially if they are of Chinese origin, there should be a high degree of
suspicion that they may have cancer of the nasopharynx and an urgent referral
to an ear, nose and throat (ENT) specialist should be arranged.
The ENT specialist will then perform an examination of the
nasopharynx. Traditionally this was performed by looking through the mouth with
a small mirror angled upwards towards the nasopharynx. However, advances in
technology mean that currently the best way to examine the nasopharynx is with
a small flexible or rigid telescope, which is passed through the patients nose
to the nasopharynx at the back. This can be done in the clinic with the patient
sitting in a chair.
The appearances at the back of the nose can sometimes be
misleading as often the tumour grows under the surface lining of the
nasopharynx and can therefore be difficult to see.
Further special tests will include a
computerised tomography (CT)
scan to assess the extent of the disease.
The specialist will also arrange a hearing test if deafness is a
symptom.
In addition the specialist will want to organise a
biopsy (tissue
sample) of the nasopharynx to obtain some tissue to send to the pathology
laboratory. Here the pathologist will examine the tissue in microscopic detail
to confirm if there are cancer cells present or not.
How is cancer of the nasopharynx treated?
By far the best treatment for cancer of the nasopharynx is
radiotherapy (X-ray treatment). These tumours are very sensitive to X-rays and
generally respond very well to treatment. More advanced tumours may require the
addition of anticancer drugs (chemotherapy) prior to the start of the
radiotherapy.
Surgery has a very limited role in treatment because of the
inaccessible nature of the nasopharynx.
What is the outlook?
The outlook for patients with cancer of the nasopharynx depends
largely on the extent of the disease at the time of diagnosis.
Of people with early (stage1) tumours, 70 to 80 per cent are
still alive five years after treatment. With more advanced stages of disease
the five-year survival rate falls and those with the most advanced tumours
(stage 4) have only a 0 to 20 per cent chance of surviving five years.
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Last updated 01.08.2005
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