2 September 2015

Nasopharyngeal cancer: Sarawak’s silent killer

By Dr Paul Neilsen

Cancer is a threat that most of us hope we will never experience. But unfortunately, this is not the case for many of us, as cancer is one of the leading causes of death in Malaysia. Cancers come in many different types and can develop in almost any tissue in our bodies. Interestingly, Sarawak has a rather unique spectrum of cancer types as compared with Peninsular Malaysia or other parts of the world. Most notably, in Sarawak there is an alarmingly high rate of cancers in the nasopharynx – an area deep within the nasal cavity located at the base of the brain. According to the most recent Malaysian Cancer Statistics report from the Ministry of Health, there are over twice as many nasopharyngeal cancers diagnosed in Sarawak as compared to Peninsular Malaysia. In fact, nasopharyngeal cancers are the most common cancer type diagnosed in Sarawakian males. This alarming statistic highlights an urgent need for us to better understand why this cancer type is so frequent in in the state. A study by Dr Beena Devi and her colleagues at the Sarawak General Hospital reported that nasopharyngeal cancers were very common among the Bidayuh community. In fact, the Bidayuh were reported to have the highest risk of developing this cancer type of any ethnic group worldwide. The Iban and Chinese of Sarawak were also associated with an unusually high risk of developing this disease. Hence, the high rates of these cancers in the state as compared to Peninsular Malaysia can be accounted for by the high rates of nasopharyngeal cancer incidence in its indigenous ethnic groups such as the Bidayuh. However, we are still yet to understand why it is that the Bidayuh have an alarmingly high risk of developing this cancer.

Sadly, nasopharyngeal cancers are difficult to treat and are typically associated with poor survival rates for the patients. Recent data from the Nasopharyngeal Cancer Database showed that only 40% of Malaysians diagnosed with nasopharyngeal cancer will survive. These rather dismal survival rates are due to the deep-seated location of this tumour at the back of the nasal cavity beneath the brain, which makes it inoperable. The only treatment options available to treat nasopharyngeal cancer patients are radiotherapy and chemotherapy. Furthermore, due to its deep-seated location, the vast majority of affected individuals don’t know they have nasopharyngeal cancer until it has already spread to the lymph nodes in the neck. Indeed, the most common first sign of nasopharyngeal cancer in newly diagnosed individuals is a lump in the neck – meaning that the cancer has already spread from the nasal cavity to other parts of the body. These advanced nasopharygeal cancers are difficult to treat once they spread and the outcomes for these patients are usually poor as the cancers are less responsive to chemotherapy. Hence, the discovery of new treatments that are more effective than the currently used chemotherapies is a major focus of the ongoing international research in nasopharyngeal cancer.

So, given the high rates of nasopharyngeal cancer in Sarawak, what should we do to improve the survival rates? Early detection is perhaps the best way to improve the chances of surviving this disease. If it is detected early before it spreads beyond the nasal cavity, then the disease is usually cured through doses of radiotherapy alone. Regular screening in high risk individuals may also lead to earlier detection and improved survival rates. Nasopharyngeal cancer tends to run in the males of families, meaning that part of the cause of this cancer is passed through generations in the genes (our DNA) that we inherit from our parents. Hence, it is recommended that if you are a male and have someone in your family that has previously been diagnosed with nasopharyngeal cancer, then it would be advisable to speak to your ENT about routine screening.

Hopefully, further research will lead to the discovery of the key factors that make the ethnic communities of Sarawak, such as the Bidayuh, at risk of developing nasopharyngeal cancers. Furthermore, it is hoped that the outcomes from research efforts will lead to the development of more effective treatments to improve the survival rates for those diagnosed with nasopharyngeal cancer.

Dr Paul Neilsen is a senior lecturer and postdoctoral researcher with the Faculty of Engineering, Computing and Science at Swinburne University of Technology Sarawak Campus. Neilsen is currently conducting research on the treatment for nasopharyngeal cancer. He is contactable atpneilsen@swinburne.edu.my