NASOPHARYNGEAL carcinoma or NPC is a disease in which a malignant tumour (cancer) grows in the nasopharynx. The nasopharynx is a small space, about 4 cm cube in size, lying behind the nasal cavities and hemmed in by the base of the skull on top and the soft palate below. The nasopharynx leads to the nostrils in the front, while an opening on each side leads to the ears. Due to its small size and inaccessibility in the past, clinicians had termed the nasopharynx a “blind spot”, “hidden cavity” or “unknown region”.
The site of origin of all NPC, a breakthrough discovery, was established by Prof U. Prasad of the Department of Otorhinolaryngology, Faculty of Medicine, University of Malaya, Kuala Lumpur in 1979, as being at the Fossa of Rosenmuller (FOR), a precise area along the lateral wall of the nasopharynx. Earlier to this, in 1974, he also found out that the cells from which NPC developed were the epithelial cells lining the FOR.
When a tumour in the nasopharynx grows upwards or to the front and back, there is a danger it will grow into the cranial cavity and damage nerves and tracts. The spread sideways, meanwhile, affects the Eustachian tube, causing “mild conductive deafness” – an important symptom for early detection. NPC is a highly malignant tumour and grows rapidly, spreading from the nose to neck nodes, bones, liver and lungs. If not diagnosed and treated effectively, the patient may die in two to three years.
Who does it affect
NPC is the fourth most common cancer in Malaysia. Ethnically, the Chinese are at highest risk (86%). Malay patients make up 15%. The indigenous peoples of East Malaysia like the Kadazans, Ibans and Bidayus are also high-risk groups. In terms of age, 75% of patients are between 30 and 59. And there are approximately three male patients to every female patient.
What are the symptoms
Most of the signs and symptoms of NPC include those involving the ear, nose, neck, eyes, and face. A doctor should be consulted if these or any of the following problems occur:
Buzzing sound and/or reduced hearing in one ear, without earache or ear discharge, may be considered one of the earliest symptoms in NPC. On examination, if the drum is intact, but looks a bit dull with conductive type of deafness, which may be mild, there’s a need to exclude NPC.
Patient usually gets a sensation of something at the back of the nose and on sniffing back, he brings out phlegm, which is blood-stained. If this happens frequently, NPC must be suspected and excluded. Patient may bring out blood-stained nasal discharge on blowing his nose, but frank fresh profuse bleeding from nose is not a feature of NPC in its early stages.
Painless progressively-increasing swelling, beginning from the upper part of the side of the neck, is very characteristic of NPC. Often it spreads to the other side of the neck and keeps growing downward in the neck.
Double vision (diplopia) and numbness of the mid-face are the result of extension of NPC inside the cranium and are considered very late symptoms.
It is unfortunate that despite the high success rate of treatment and knowledge about symptoms and availability of diagnostic methods, up to 80% of patients are diagnosed at an advanced stage.
What are some of the diagnostic methods
Examination procedures and the investigations that are used to detect and diagnose NPC include:
The doctor makes a complete general examination of the ear (including hearing tests), nose, throat and eyes, with special attention to the nasopharynx (nasopharyngoscopy) and the neck.
The best way to visualise the nasopharynx is by inserting an endoscope (a thin, lighted tube) through the patient’s nose. The doctor can clearly see the lesion (if there is any) or look for any abnormality in the suspected area which is brightly illuminated. He can also take a biopsy (removal of tissue for the purpose of microscopic examination to confirm the diagnosis of NPC), if necessary.
This creates a series of detailed pictures of areas inside the body, taken from different angles. The pictures are created by a computer linked to an x-ray machine. This test is also called computerised tomography. Results of CT scans determine the extent of disease. It is a MUST before treatment is started.
A procedure in which a magnet linked to a computer is used to create detailed pictures of areas inside the body. It is an optional examination.
Laboratory procedures that involve testing samples of blood, urine, or other substances or tissues in the body to help determine the plan of treatment and monitor the course of disease over time.
These are carried out to exclude spread of disease into bone, liver and/or lungs. Patients may undergo bone-scan, liver-ultrasound and chest x-ray.
What is the treatment
Radiotherapy alone is considered adequate for total control of NPC at its early stage while a combination of radiotherapy and chemotherapy is a must for those at advanced stage and without distant spread to bone/live/lung. For the later group, only chemotherapy is recommended.
What are the chances of survival
According to database maintained by Professor U. Prasad at the University of Malaya Medical Centre (formerly Universiti Hospital), since 1988 all the NPC patients who were diagnosed to be at stage I, and had completed the full course of radiotherapy are still surviving.
Even for those at advanced stage of disease (II, III &IV, without distant spread) the chance of five-year survival is as good as 80.1% (as reported by Prasad in the International Cancer Journal) if such patients receive full course of radiotherapy followed in three weeks by three courses of chemotherapy). If such patients are treated with radiotherapy alone the chance of five-year survival is reduced to 45% only.
What causes NPC
Combination of at least three factors: Genetic, Epstein-Barr virus (EBV) and some dietary factors seem to be responsible in the causation of NPC.
There is some evidence that links NPC to prolonged intake of salted fish and other preserved food, which contains EBV-activating agent.
The EBV, which is often picked up in early childhood, remains dormant through out whole life in normal human beings.
When activated, it plays a causative role, under genetic influence, in the pathogenesis of NPC.
This role was first established by a group, led by Professor R. Pathmanathan and Professor U. Prasad of the University of Malaya in collaboration with the University of North Carolina, USA, led by Professor Nancy Raab-Traub.
What should I do
If you are a Chinese (the highest risk-group)or a Kadazan or an Iban or a Malay (intermediate risk-group) between the ages of 30 and 60, and have any of the symptoms as mentioned above, it is almost mandatory to get NPC excluded. Even if you are not in those groups, watch out for those symptoms and consult an Ear, Nose and Throat specialist if you suspect anything is amiss. Early detection could save your life.
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