Nasopharyngeal Carcinoma

Nasopharyngeal Carcinoma, also known as “Canton tumor” due to its high prevalence in Southern China, is one of most common cancers in Hong Kong. There are about 900 new cases per year in Hong Kong. The incidence rate is 3 times higher for men, and the peak incidence age is around 50 to 60.

Early awareness is important. If Nasopharyngeal Carcinoma is discovered at an early stage, the cure rate is high. For stage I disease, the cure rate is about 90%.

(Special thanks to Dr. Wing Mui Anne LEE, Chief Of ServiceNg Wai Tong, Consultant, Clinical Oncology, Pamela Youde Nethersole Eastern Hospital for reviewing the information of this page.)

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Nasopharynx is a centrally located region in the head, between the posterior part of the nasal passage and the soft palate, and is connected to the pharynx underneath. Nasopharyngeal Carcinoma is a malignant tumor in the nasopharynx.

Nasopharyngeal Carcinoma is the most common head and neck cancer in Hong Kong.

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The causes for Nasopharyngeal Carcinoma are not fully known. Suspected causes include:

Heredity:first degree relatives (including parents, siblings, and children) of a Nasopharyngeal Carcinoma patient have a higher risk of suffering from the same cancer than others.

Diet: Chinese ranks number one in the world for suffering from Nasopharyngeal Carcinoma, with an even higher incidence rate in Southern China and Hong Kong, which may be related to the predilection for salted fish and pickled vegetables. Animal experiments also showed that excessive intake of salted fish may induce nasal cancers.

Lifestyle: smokers might have a slightly higher risk of developing Nasopharyngeal Carcinoma.

EB Virus: EB Virus (Epstein-Barr Virus) infection may result in symptoms similar to that of common cold. Blood serum of most Nasopharyngeal Carcinoma patients contains one or more antibodies directed against EB Virus.

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The first step towards prevention is to maintain a healthy dietary habit:

  • Avoid salted, pickled food, and cut down on canned or preserved food.
  • Be vigilant: if symptoms occur, especially swollen neck lymph nodes, consult a doctor as soon as possible.
  • Regular checkup: If you have family history of Nasopharyngeal Carcinoma, you are advised to have regular checkups.
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Malignant transformation occurs to surface cells in nasopharynx – the real causes are unknown.
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相片 Nasopharynx is a non-exposed organ. In the early stage of Nasopharyngeal Carcinoma, there are no obvious symptoms. However, when the tumour grows and spreads into the surrounding tissues, the following symptoms may appear:

  • Stuffiness, nose bleeding or blood stained sputum
  • Hearing loss, tinnitus (ringing in the ear) or discharge from the ear canal
  • Swollen neck lymph nodes
  • Headache: sustained migraine (a severe recurring throbbing headache), especially at night
  • Facial paralysis, double vision, hoarse voice, difficulty in swallowing

If the above symptoms persist for more than two weeks, you should visit your family doctor as soon as possible. Your doctor may refer you to an oncologist (a specialist in tumors) or otolaryngologist (ear-nose-and-throat doctor) for further checku.

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People with higher risks or the above symptoms should visit their doctor and have checkups regularly or as soon as possible, because early diagnosis can increase the cure rate. The following checkups are recommended:

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  • Blood taking: to measure the antibodies directed against EB Virus in blood serum
  • Endoscopy : to check for any abnormality in the nasopharynx
  • Biopsy: if abnormalities are found in the nasopharynx, doctor may need to extract some tissues for testing

Once Nasopharyngeal Carcinoma is confirmed, the doctor will arrange further tests to determine the tumor extent and whether the cancer cells have spread to other organs, including:

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 相片The doctor may suggest the following treatments:

(I) Radiotherapy
This is the mainstay of treatment for Nasopharyngeal Carcinoma. External radiotherapy uses high-powered radiation beams to destroy cancer cells. Treatment will be carried out on a daily basis for six to eight weeks

Nowadays, intensity modulated radiotherapy is used in treating Nasopharyngeal Carcinoma. This treatment allows highly precised radiation beams to be concentrated at the tumor. This could effectively kill tumor cells and at the same time reduce radiation damage to the surrounding normal tissues.

(II) Chemotherapy
The doctor may consider using radiotherapy and concurrent chemotherapy on selected patient to enhance the effectiveness of treatment. The doctor will give chemical drugs through the blood vessels before radiotherapy to enhance the potency of radiotherapy.

If the tumor has metastasize to other organs, chemotherapy may also  help to  relieve symptoms caused by the tumor.

(III) Surgery
As the nasopharynx hides deeply in the middle of the head, and it is very close to a number of major structures e.g. the brain stem, it is not easy to conduct surgery on the patient. Therefore, surgery is not the first line treatment for Nasopharyngeal Carcinoma. Nonetheless, under certain special circumstances, surgical removal of the tumor may be suggested for the patient, such as early tumor recurrence.

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Radiotherapy

During the early weeks of radiotherapy, the patient may suffer from nausea, dry mouth, taste changes, loss of appetite, etc. In the later weeks, patient may have mouth ulcers, skin darkening, throat pain and hair loss, etc. However, these will gradually subside a few weeks after the completion of the treatment. But for some patients, they may continue to suffer from dry mouth as their salivary glands will produce less saliva because of the radiotherapy. In addition, the patients may have following conditions:

  • They may have otitis media (inflammation of the middle ear) , which causes partial hearing loss .
  •  They may have stiffness of temporomandibular joint (the jaw joint) , thus causing a ‘lockjaw’ sensation.
  • A minority of the patients may have disturbed  endocrine function, or impaired nerve function.

Chemotherapy

Although anticancer drugs can kill cancer cells, they also affect the division of normal cells. Patients may suffer from vomiting, hair loss, diarrhea, loss of appetite, anemia (a deficiency of red blood cells), reduced white blood cells, and thus lowered immunity; so patients may be infected more easily. In addition, the kidney function may also be affected.

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Patients need to be aware of many issues before and after radiotherapy and during recovery. More understanding can help patients face the illness positively.

Regular follow-up

  • • After radiotherapy, patients may have complications such as otitis externa (inflammation of the external ear), dermatitis (inflammation of the skin) or malfunctioned organs etc. Regular follow-up ensures appropriate treatment.
  • Regular follow-up may also allow early detection and treatment of recurrence or metastasis, which allows early treatment

Prevention of decayed teeth and mouth infection
Radiotherapy will reduce secretion of the salivary glands, so patients may have higher chances of tooth decay. Therefore, they should:

  • Consume less sweet food and drinks, brush their teeth immediately after meals, and visit dentists regularly for checkups.
  • Keep mouth moist: patients may wipe mouth with clean gauze moistened with salt water before they sleep.
  • Stop smoking and alcohol drinking to prevent exacerbation of dry mouth..

Radiotherapy may cause lockjaw. Patients should do mouth exercises every day to enhance flexibility of their mouth.

Diet

  • Patients should consume a high protein and high caloric diet to help speed up recovery.
  • Avoid foods that are deep fried, spicy, or dry and hard
  • Drink nutritious supplements to increase energy intake.

Skin care

The skin and lips within the radiotherapy treatment area may be burnt. Patients should:

  • Avoid using soap, medicated cleanser and skin lotion. Use mild skin lotion instead
  • Avoid direct sunlight and UV light.
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  • To surrounding areas like neck lymph nodes
  • To more distant areas, such as the bones, bone marrow, lungs, and liver
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