KUALA LUMPUR, Oct 1 — Although nasopharyngeal cancer (NPC) is a relatively rare cancer globally, Malaysia remains one of the countries with the highest burdens of the head and neck cancer, experts say.
Dr Mohamed Ibrahim Abdul Wahid, medical director and consultant clinical oncologist at Beacon Hospital in Selangor, noted that in 2020, Malaysia ranked fourth worldwide for incidence of NPC, also known as nose cancer.
“More than 80 per cent of global NPC cases occur in Asia, with Malaysia recognised as an endemic region alongside southern China and Southeast Asia,” Dr Ibrahim told CodeBlue.
According to the National Cancer Institute (IKN), although the number of NPC cases in Malaysia increased from 4,597 in 2012-2016 to 5,186 in 2017-2021, incidence declined from 4.0 per 100,000 population to 3.1 per 100,000 population in the respective periods, based on the Malaysia National Cancer Registry Report (MNCRR).
High-Risk Communities: Bidayuh/Other Bumiputera, Chinese, Male
“NPC is the sixth most common cancer among males in Malaysia,” IKN told CodeBlue.
The overall lifetime risk for males is estimated at one in 167, with the highest risk observed among the Chinese and Other Bumiputera (one in 100).
Among females, the lifetime risk was one in 500, with the highest risk observed among Other Bumiputera females (one in 250).
In the MNCCR, Other Bumiputera refers to the indigenous populations of Malaysia apart from Malays, including the Orang Asli of Peninsular Malaysia and the native ethnic groups of Sabah and Sarawak, such as the Iban, Bidayuh, Kadazandusun, and Murut.
Within Malaysia, Sarawak continues to record the highest incidence of NPC, with rates of 10.6 per 100,000 among males and 3.9 per 100,000 among females, according to IKN.
The national cancer institute highlighted differences between ethnicities when it comes to NPC incidence in Malaysia.
“The incidence rate is still higher among Chinese and Other Bumiputera populations compared to Malays and Indians. Notably, among Other Bumiputera, the incidence rates have remained relatively unchanged, despite the overall national decline,” IKN told CodeBlue.
Citing a 2021 study by Linton et al, IKN noted that the Bidayuh community specifically in Sarawak has historically recorded NPC incidence rates comparable to some of the highest in the world at age-standardised incidence rates (ASR) of 24.6 per 100,000 among males and 9.3 per 100,000 among females for the period of 2007 to 2011.
This was similar to high-incidence regions in southern China.
However, IKN cited more recent unpublished data from the Sarawak state health department indicate a declining trend in incidence within the Bidayuh community, with ASR decreasing from 39 per 100,000 (1996–2000) to 22 per 100,000 (2011–2015).
“This suggests that, while the rates remain relatively high, there has been progress in reducing the burden of the disease over time.”
The ASR data cited by IKN of 22 per 100,000 among the Bidayuh community (2011-2015) shows that NPC incidence in the indigenous group was much higher than the national rate of 3.1 per 100,000 population (2017-2021).
Why Bidayuh Are Particularly Vulnerable To NPC
Dr Pua Kin Choo, an otorhinolaryngologist in Gleneagles Hospital, Penang, described the high NPC risk among the Bidayuh as multi-factorial, including genetic susceptibility to mutation of Epstein Barr Virus (EBV) at the nasopharynx and family history of NPC.
She also cited exposure to environmental hazards like wood solvents containing hazardous chemicals; tobacco smoking; and consumption of salted preserved fish, meats, or vegetables that may contain carcinogenic nitrosamines.
IKN cited similar reasons for the higher risk of NPC among the Bidayuh community, saying: “This means that NPC does not have a single cause, but rather results from several interacting risk factors.”
According to National Cancer Society of Malaysia (NCSM) managing director Prof Dr M. Murallitharan, EBV infection causes more than 95 per cent of endemic NPC cases.
Dr Ibrahim said these factors reinforce the need for targeting screening and prevention in high-risk groups.
Hard To Detect NPC, Early Symptoms Are Mild
NPC is often detected too late in Malaysia because the tumour is tucked away where it can’t be seen, experts said.
About 76.2 per cent of males and 72.6 per cent of females with NPC in Malaysia are diagnosed at the late stages of three and four.
“Because the tumour hides deep in the nasopharynx, early symptoms are mild and easily dismissed. By the time symptoms are severe enough to prompt clinical investigation, the cancer has fundamentally advanced,” explained Dr Murallitharan.
He stated that key warning signs include a painless neck lump (the most common presentation), nose bleeding, blocked nostrils, excessive mucus secretion, and blood in saliva; unilateral ear block, hearing loss, or tinnitus as well as headaches, facial numbness, or cranial nerve problems.
IKN said screening is most effective for individuals with a family history or those in high-incidence populations. Currently, there are a few ways to screen for NPC.
“Serological screening using blood for VCA IgA and EA- IgA are commonly used, but very nonspecific. EBV DNA screening is useful but can be costly. Nasoendoscopy is very useful, just like how MRI and PET scans are useful for suspicious cases,” Dr Pua said.
Dr Ibrahim also mentioned the EBV test and Multi-Cancer Early Detection (MCED) tests.
When the cancer is identified, the treatment plan depends heavily on the stage. “Radiotherapy alone in early stages of cancer. Radiotherapy with chemotherapy in late stages of cancer. Surgery is reserved for recurrent cases,” said Dr Pua.
Dr Murallitharan said radiotherapy is the primary treatment modality for NPC. Intensity-Modulated Radiotherapy (IMRT) is preferred to spare critical structures (e.g., salivary glands, brainstem). If there is a recurrence, nasopharyngectomy or re-irradiation is done.
According to the 2018 Malaysian Study on Cancer Survival (MySCan) report, relative five-year survival rates for NPC were slightly higher for women (49.2 per cent) than men (44.8 per cent).
Five-year relative survival rates increase when NPC is detected earlier: stage one (63.7 per cent), stage two (59.1 per cent), stage three (50.2 per cent), and stage four (26.9 per cent).
“This highlights the importance of early diagnosis and timely treatment,” IKN told CodeBlue.
