Studies have shown that the Epstein Barr Virus (EBV) is a likely cause, although the presence of EBV does not automatically mean one has or will have NPC. Other implicated factors are polycyclic hydrocarbons (compounds produced in the burning of fossil fuels, like charcoal), nitrosamines (chemicals in preserved foods, like salted fish) and poor hygiene. There is also a strong heredity factor. People with a family history of NPC are predisposed to it and should be particularly aware of early symptoms.

Symptoms of NPC

NPC often originates in the back of the nose and above the soft palate, so it is often not visible of noticeable until it is very large or when it causes other symptoms. Therefore, NPC is often diagnosed late. Those who are predisposed to NPC need to be aware of the early symptoms, such as:

• Blood-stained sputum, usually first thing in the morning. Any bleeding from a tumour usually flows into the throat overnight. In rare cases, there may be bleeding from the nose.
• A "blocked" sensation in the ear, hearing loss or tinnitus (a ringing sound) for no apparent reason. The tumour often occurs where the Eustachian tul›e of the ear opens into the nose and may affect the normal functions of the Eustachian tube. The blocked sensation would be similar to the sensation one might experience when landing in a plane.
• Abnormal, persistent lumps in the upper neck. NPC often spreads to the lymph nodes in the neck.

Later-stage NPC symptoms include blocked nose, headache and problems with cranial nerves, eye-movement and vision. Eventually, the cancer may spread to the bones, lungs and liver.