The nasopharynx is the area where the back of the nose turns to meet the upper section of the throat. The cancerous tumour usually originates at the curved part behind the nose or the post nasal space. As the tumour is situated close to critical structures of the brain, spinal cord and throat, nasopharyngeal cancer can cause many symptoms in its advanced stages.
It is common among the Chinese population, particularly in Hong Kong and Southern China. In Malaysia, we are talking about an incidence of 25 cases for every 100,000 people in the population.
According to the recent National Cancer Registry, nasopharyngeal cancer is the second most common cancer in Malaysian men, after lung cancer. In comparison to the rest of the world, the Malaysian Chinese male has the second highest incidence; the local Chinese women have the highest incidence in the world.
The incidence rises with age, particularly between the ages of 50 and 60. But as our population expands, we are definitely seeing more cases in recent years.
An epidemiology study in Hong Kong many years ago found an association between eating salted fish at a young age and the occurrence of nasal cancer. However, recent studies have implicated viral origin of the disease. He virus implicated is known as the Epstein-Barr virus. While many of us have that virus sitting dormantly behind our noses, some of us will eventually develop cancer due to the complex interaction of the virus and our genes. Other environmental factors include the consumption of preserved food and fermented fish products, as well as exposure to toxic fumes and tobacco.
Early symptoms include:
hearing problems, such as ringing and tingling
As the disease progresses, symptoms may include:
numbness in the face
coughing out blood
breathing difficulties caused by a blocked nose
The first stage of diagnosis involves a full ENT (ear, nose and throat) examination by a specialist, which includes examining the back part of the nose. If a swelling or bulge is present, a biopsy is indicated. A biopsy involves removing a small piece of tissue sample to determine the presence of cancer cell. It is essential in making a diagnosis.
The ENT specialist is usually the first port of call for patients, as most of them think of their symptoms as common ENT problems. As soon as the ENT specialist detects something amiss or the biopsy is confirmed for cancer, the patient will be referred to an oncologist. The role of the clinical oncologist is to treat the cancer with radiotherapy or chemotherapy, or both.
More tests will be done to determine the extent of disease and the best way to treat the patient. This includes a computed tomography (CT) scan or magnetic resonance imaging (MRI) of the head and neck area. X-ray or scans of the chest, liver and bone are also necessary to find out if the cancer has spread to those areas.
At Stage I or II of the disease, where the tumour is confined to the back of the nose, the treatment choice is radiotherapy. Radiotherapy is an X-ray treatment using high-energy radiation to kill cancer cells. Radiation is given to the tumour site, which will also include the neck and throat. It is given daily from Mondays to Fridays for 7 weeks. At these early stages, treatment can achieve a cure rate of over 90% and recurrence is very unlikely if an experienced oncologist administers it.
At Stages III and IV, when the lymph nodes have become infected with tumour (but the tumour has not progressed to other parts of the body), treatment is a combination of radiotherapy and chemotherapy. When both treatments are done concurrently, a cure of between 60% to 70% can be achieved compared to radiotherapy alone. The side effects are greater with combination treatment, but this is offset by higher cure rates.
Short-term complications start with dry mouth and loss of taste. This could lead to loss of appetite. By the 3rd and 4th week of treatment, there will also be difficulty in swallowing, which will persist throughout treatment. There may be some skin changes in the treated area. Fortunately, these side effects are only temporary and will last until treatment is completed. The taste capacity takes about 2 months to recover, while the dry mouth never fully recovers, but itís a small price to pay for cure.
However, newer treatment techniques using CT scan-based treatment planning may help reduce these long-term side effects.