Nasopharyngeal cancer often afflicts Chinese men, but early diagnosis can raise survival prospects.
It is referred to as Cantonese cancer because of the high incidence among people from China’s Guangdong province and Hong Kong. But nasopharyngeal cancer (NPC), or nose cancer, is also common among Chinese from neighbouring Fujian province and other parts of southern China.
In Singapore, 80 per cent of people with the disease are Chinese, with Malays and Indians comprising a small minority. However, the actual numbers afflicted with the cancer are relatively small — over 1,000 cases between 2013 and 2017, according to 2017 National Cancer Registry statistics.
“SingHealth sees around 180 NPC patients each year, of which 60 per cent are diagnosed in the advanced stages,” said Associate Professor Lim Chwee Ming, Senior Consultant, Department of Otorhinolaryngology – Head & Neck Surgery, Singapore General Hospital (SGH).
NPC occurs in the cells lining the area behind the nose and just above the back of the throat. It is often discovered late as it displays few symptoms in the earlier stages. Moreover, symptoms may also be mistaken for more common ailments, such as cough and flu, said Dr Soong Yoke Lim, Senior Consultant and Deputy Head, Division of Radiation Oncology, National Cancer Centre Singapore (NCCS).
“When the tumour is very small in the nasopharynx (back of the nose), patients sometimes experience blood-tinged saliva. Patients may think it is due just to ‘heatiness’ and get cooling herbal tea from traditional Chinese medicine shops. That can delay the diagnosis,” Dr Soong added. Other red flags include a painless lump in the neck, nasal discharge, a blocked ear, or hearing loss on one side. In some rare cases, NPC can cause double vision.
It is not known what exactly causes NPC, but a combination of genetic and environmental factors plays a role. Those with close relatives who have the disease have a greater chance of getting NPC.
NPC is also associated with the Epstein Barr virus (EBV), a member of the herpes virus family that spreads via body fluids, such as blood and saliva. Although 80 to 90 per cent of the world’s population harbour the EBV, the majority do not experience symptoms or recover from the infection without realising it.
Anyone can get nose cancer, but it typically affects men in the prime of their lives between the ages of 35 and 55 years. It is the 10th most common cancer among Singapore men, according to 2017 Singapore Cancer Registry figures.
Nose cancer is treatable, and patients mostly live longer than those suffering from other cancers, such as lung cancer. The chances of NPC patients living five years after diagnosis range from around 90 per cent for stage 1 cancer to around 60 per cent for stage 4. In contrast, the five-year survival rate for stage 4 lung cancer is under 10 per cent, said Dr Soong.
In Hong Kong and Taiwan, the disease is on the decline but it is not clear why. Better diet in those places may be one reason, as studies have shown that NPC is linked to an early diet that is high in preserved foods, especially salted fish. Eating more fresh fruit and vegetables, as well as regular exercise are some ways that help reduce the risk of getting not just nose cancer but cancers in general, said Dr Soong.
According to Prof Lim, early-stage NPC is treated with radiotherapy, while chemoradiotherapy (chemotherapy given concurrently with radiotherapy) is used for disease that has advanced but not spread. If the cancer recurs, surgery is an option; but if it cannot be safely or effectively performed, repeat radiotherapy and chemotherapy are options, Prof Lim said.
“It is a radiosensitive cancer, which means that it responds well to radiotherapy, and the success of treating non-metastatic cancer (cancer that has not spread) is generally good,” explained Prof Lim.