Nasopharyngeal Cancer

Nasopharyngeal cancer (NPC) used to be known as “Guangdong cancer” for its prevalence in southern China. As the early symptoms are not very noticeable, the disease is often neglected until an advanced stage. Its high incidence in the past might be explained by people’s frequent consumption of salted food such as fish and vegetables. With reduced intake of these foods, the disease is occurring less commonly than before.

Nasopharyngeal cancer is the 7th most common cancer in Hong Kong. In 2008, there were 926 new cases and the incidence was 13.3 per 100,000. Although it mainly affects male above the age of 40, those in their 30s can also develop the disease.
 
Causes and Risk Factors
  • Family history of having a direct relative who has had nasopharyngeal cancer plays a major role in the development of the disease;
  • Infection with the Epstein-Barr virus (EBV), a common virus spread by droplets, is associated with nasopharyngeal cancer in some patients;
  • Genetic factors: Research suggests that people with certain genetic make-up are at an increased risk of developing nasopharyngeal cancer;
  • Diet: Frequent consumption of salted food such as fish and vegetables may increase a person’s risk of having the disease.
 
Common Symptoms
Symptoms of early nasopharyngeal cancer:
  • Persistently having blood-stained nasal discharge or sputum;
  • Pain, tinnitus and trouble hearing, especially on one side only;
  • Enlarged neck lymph nodes (the area below the ears and lower jaw).
Symptoms of advanced nasopharyngeal cancer:
  • Headache and facial numbness;
  • Blurred or double vision;
  • Difficulty swallowing and hoarseness of voice.
The early symptoms are often neglected. If detected and treated early, more than 90% of the patients can be cured.

Diagnosis

The following procedures are indicated for patients who are suspected to have nasopharyngeal cancer:
  • Nasopharyngoscopy: A flexible optical instrument is passed into the nose or mouth to look at the nasopharynx. Cell or tissue samples can be taken for biopsy during the procedure.
  • Biopsy: Cell samples taken from the nasopharynx are examined under a microscope to look for abnormalities, determine whether nasopharyngeal cancer is the major cause of neck lymph node enlargement and find out whether cancer cells have spread to neck lymph nodes.
  • Blood test: This is to detect EBV-DNA and/or the IgA-VCA antibody in serum.
  • PET-CT scan and MRI: The high sensitivity and accuracy over conventional diagnostics make them an effective tool in detecting early nasopharyngeal cancer and monitoring tumour recurrence and metastasis.
Treatments
The following types of treatment may be given alone or together, depending on the patient’s condition:
  • Radiotherapy is the mainstay of treatment for nasopharyngeal cancer, with Intensity-modulated Radiation Therapy (IMRT) as the gold standard. IMRT enables the therapist to adjust the intensity of the radiation beams, thus precisely enveloping the tumour in a high dose while sparing normal tissues. IMRT is more effective in local disease control and preservation of normal organ functions. The ground-breaking TomoHD is now in use in the Hospital and is capable of more even dose distribution, mitigating side effects after radiotherapy.   
  • Chemotherapy is given in combination with radiotherapy to remove cancer cells in the head, neck and other organs.
  • Surgery may be performed if there is residual disease or recurrence after radiotherapy or combination therapy. Stereotatic Surgery (also known as X-knife) treats localized residual disease while conventional surgery removes the local tumour and affected neck lymph nodes.
Early nasopharyngeal cancer can be treated with radiotherapy alone. For mid-and-late stage disease, combination therapy should be used. Doctors will plan the most appropriate treatment according to the patient’s condition.

Screening
Those whose direct relatives have had nasopharyngeal cancer are at an increased risk. As the age of disease onset is usually about the same in a family, they are recommended to start having regular screening 5 to 10 years before the onset age. Blood test is an effective screening tool because EBV-DNA and/or the IgA-VCA antibody are often found in the serum of nasopharyngeal cancer patients.

Among the cases confirmed by screening, approximately 50% are classified as Stage I, while it drops to fewer than 10% when clinical symptoms surface. Early detection is thus crucial to the clinical outcomes of cancer treatment.

We provide a nasopharyngeal cancer screening package for those with a family history of the disease. Procedures consist of basic physical examination, medical history taking, blood test for the presence of EBV-DNA and/or the IgA-VCA antibody and follow-up. Please contact us for details.

We also provide patients and their relatives with education on the nature and specifics of the related malignancy, diagnosis and treatment.

Preventions
In nasopharyngeal cancer, diet is the only risk factor that can be modified to prevent the disease from happening. Dietary modifications mean avoiding salted food and eating plenty of fresh fruits and vegetables. As a healthy lifestyle always helps to prevent diseases, it is also important to exercise regularly and stay away from smoking. Those at an increased risk of nasopharyngeal cancer should have regular screening tests so that the disease can be detected early if they become unfortunately affected.