SINGAPORE: On Monday (Jun 17), the Agency for Science, Technology and Research's (A*STAR) Genome Institute of Singapore (GIS) announced a scientific discovery that could pave the way for the early detection of what it describes as Cantonese cancer - the most common head and neck cancer in Singapore.
Here are five things to know about the disease.
WHAT IS IT?
Nasopharyngeal carcinoma or nose cancer, is often referred to as Cantonese cancer because of its prevalence among the Chinese, particularly those from the Cantonese dialect group.
It affects the nasopharynx, which is the area behind the nose and above the back of the throat. The cells that line the nasopharynx can become cancerous and give rise to the condition, also referred to as NPC, according to the SingHealth website.
Science as well as Nature Genetics are two examples of research journals that refer to the disease as Cantonese cancer.
A painless lump in the neck is found in nearly 75 per cent of newly diagnosed NPC, the website stated.
Individuals who see the following symptoms develop and persist - a painless lump in the neck, excessive nose discharge, blocking or bleeding, decreased hearing or ringing in the ears, pain or numbness in the face, double vision or headache - are advised to consult a doctor, it added.
READ: Singapore scientists discover new viruses that help identify individuals at high risk of Cantonese cancer
WHO ARE MOST AT RISK?
The exact causes of NPC "are not yet known", according to the Gleneagles Hospital website, although there are risk factors that increase one's chances of developing it.
These include smoking and infection by the Epstein-Barr virus (EBV). EBV is associated with NPC development as the virus been found in nearly all NPC cells.
"However, an EBV infection on its own is not enough to cause NPC," the website stated.
Besides being more common among Cantonese people, NPC also affects more men than women.
According to SingHealth, it is the eighth most common cancer among Singaporean men and affects those between the ages of 35 and 55. It is also the most common head and neck cancer in Singapore.
On its website, the Gleneagles Hospital also suggested that NPC is linked to certain dietary habits.
The disease is "very common in areas of Asia, northern Africa and the Arctic region, which are known for diets that are high in salt, cured fish and meat", it stated.
To lower one's risk, SingHealth recommended a diet of fresh fruit, green vegetables and other sources of vitamin C. It also warned against consuming excessive amounts of salted fish and other preserved foods, as well as "active and secondary" exposure to tobacco smoke.
On Monday, a study by Singapore scientists was published noting the discovery of two EPV variants. Individuals infected by the unique strain of EBV carrying these two variants were found to have 11 times higher risk of developing NPC than non-carriers.
"This unique strain seems to have originated in Asia, followed by expansion in NPC-endemic regions," said GIS said in a press release.
Lead author of the study, Dr Liu Jian Jun, said the study provided "novel insights into the NPC endemic" and "potentially provides the basis for implementing effective intervention programmes to reduce its incidences".
Executive director at GIS, Professor Ng Huck Hui also said that the discovery has "important implications for public health efforts to reduce the burden of NPC, particularly among Cantonese speakers".
"Testing for these variants enables the identification of high-risk individuals for routine clinical monitoring to detect NPC early.
Primary prevention through the development of vaccines against high-NPC-risk EBV strains is expected to greatly reduce the incidence rate of Cantonese Cancer," Prof Ng added.
Early nasopharyngeal cancer is treated by radiotherapy, while chemotherapy is sometimes used as part of the treatment.
"Due to the location of the cancer, surgery is not commonly used," SingHealth stated on its website, adding that "in some patients, surgery may be used to remove lumps in the neck that have persisted or returned after treatment with radiotherapy".
Surgery may also be considered when the cancer in the nasopharynx recurs despite radiotherapy and there is no spread of cancer elsewhere in the body.
"With prompt and appropriate treatment, the outlook for a person with nasopharyngeal cancer is reasonable. Early disease limited to (the) nasopharyngeal (area) can be cured with radiation in large majority," said SingHealth.