TVB News Medical Series – Nasopharyngeal Cancer
Nasopharyngeal Cancer is the most common head and neck cancer.It has an early age of onset compared to other cancer, usually between age of 40 to 50 years old. Men are two times more likely than women to develop Nasopharyngeal Cancer. What is the cause of this cancer? Is there any way to prevent it?
Nasopharyngeal Cancer is also called “Guangdong Cancer” because incident rate of this cancer is particularly high in Southern China. Hong Kong has more than one thousand new cases each year. There are studies that indicate fondness of eating salted fish and other salt preserved foods as a contributing or carcinogenic factor for Nasopharyngeal Cancer. Although this theory is uncertain, medical community believes that consuming less of salt preserved foods can minimize risk or prevent development of Nasopharyngeal cancer. In Southern China, almost all patients with Nasopharyngeal Cancer have Epstein-Barr Virus infection and become carrier of the virus.
What is Epstein-Barr Virus? “Epstein-Barr Virus is a common virus. In fact, over 90% of people have come in contact with this virus by the time they reach their adulthood or have antibodies to the virus. For some patients, this virus might have hidden itself in the nasopharyngeal mucosa and the virus DNA gets incorporated into the normal cells and induces the development of Nasopharyngeal Cancer.” said Dr. Dora Kwong, Clinical Professor, Head of Department of Clinical Oncology.
Nasopharynx is about three centimeters behind the nasal cavity position. Symptoms of Nasopharynx and tumor growth is closely related. If close to the nasal cavity, patient will have symptoms like stuffy nose, nose bleeds, postnasal drip and other symptoms. If the tumor blocks the Eustachian tube, the tube that connects to the middle ear, patients will have symptoms like ringing in the ear or hearing loss because of the build up of fluid. Cancer cell can easily spread to neck lymph nodes, over seventy percent of patients have swollen neck lymph nodes problem, but not everyone has symptoms. In order to diagnose, a thorough check up is necessary,
ENT Specialist will use an endoscope or called Nasopharyngoscopy, insert into the patients nasopharyx through the nose and look for abnormalities. If suspicious of tumor, a biopsy sample may be taken to find out if the tumors contain cancer cells. This check requires anesthesia and there will be wound in the biopsy areas. With Epstein-Barr Virus as an indicator, before doing naso-endoscopy patients can go to their family doctor first and use a small brush to do a preliminary examination
Dr. Kwong Explained “The brush can enter the nasopharynx through the mouth. With the mouth open, the brush go pass the uvula up to the nasopharynx, and it’s a simple windshield movement. Cells would be deposited onto the brush tip. We will then take it for analysis. If Epstein-Barr Virus DNA is found, patient will need to find an ENT doctor to look at the nasopharynx more closely then. There may be the need to take a biopsy sample to check whether the patient has Nasopharyngeal cancer or not because the brushing test is only a preliminary examination. It cannot replace the traditional diagnosis method by doing a biopsy.”
This test is suitable for patients with no symptoms or those individuals who have a family history of this cancer. The test is paid for by the patient, the cost is around two thousand dollars (HKD). Samples will be shipped to Canada for analysis, report will be available within one to two weeks.
Air Date: 2014-08-11