SINGAPORE – It was a persistent sore throat that would not go away even after two visits to a general practitioner. Mr Choy Chan Hong had a niggling suspicion that it could be something worse, having lost his father to nose cancer. 

Then 41, he got a referral to see an ear, nose and throat specialist at the National University Hospital (NUH). His worst fears were confirmed when he was diagnosed with stage 4A cancer in May 2017. 

“I was in my early 40s, and I was dreaming of career, cars and condos. Cancer is the last ‘C’ you would be dreaming of,” said the civil servant, who is now 47. 

“You can get a sore throat from eating potato chips the night before. How would someone know if the sore throat is because of chips or because of cancer?” 

To evaluate tools for the early diagnosis of nose cancer, the National University Health System (NUHS) will be rolling out screening for the disease at three more polyclinics as part of a five-year study. 

The study is part of an integrated research programme involving the National University Cancer Institute, Singapore, the National Cancer Centre Singapore and the Agency for Science, Technology and Research’s Genome Institute of Singapore to detect nose cancer earlier and to improve patient survival rates. 

The study, which was launched last November and is being conducted at Jurong and Pioneer polyclinics, was recently extended to Bukit Batok, Choa Chu Kang and Clementi polyclinics. 

Over five years, NUHS hopes to recruit 15,000 male and 5,000 female participants between the ages of 35 and 60 for the study. 

So far, it has recruited 2,200 patients. Those who meet the age criteria and are of Chinese, Malay or mixed heritage can register their interest online. 

The screening will be free for participants, and will consist of providing blood for a serology test, self-collection of saliva and a questionnaire. 

To detect those who are at risk of nose cancer, the study will use an early antigen serology marker to pick up the presence of the Epstein-Barr virus (EBV) in the nose, said Dr Joshua Tay, a consultant at NUH’s department of otolaryngology – head and neck surgery. 

EBV has been linked to nose cancer as it has been found in nearly all nose cancer cells, he said. 

Those who test positive for the marker will be considered to be at high risk and referred to specialists at NUH for further testing. 

Associate Professor Thomas Loh, a senior consultant at NUH’s department of otolaryngology – head and neck surgery, said: “This study will allow us to reach out to the at-risk population in the community, to identify and effectively treat early-stage disease.” 

It is also hoped that the study can help to develop a cost-effective and practical screening model to dramatically increase the early diagnosis of nasopharyngeal cancer, he added. 

Dr Tay said that while over 90 per cent of the world’s population has been infected by EBV, it is still unclear why only some individuals develop nose cancer. 

“There are certain EBV subtypes that might be associated with nose cancer. People with these subtypes may have a higher risk of nose cancer than people with normal subtypes,” he said. 

“We want to be able to describe what are the subtypes in the general population in Singapore, and what subtypes we see in patients. We also want to think about whether we can use subtypes as screening tools.” 

If nose cancer is detected and treated early, survival rates are higher, with a 10-year survival rate of above 90 per cent for patients with stage 1 cancer, compared with a 10-year survival rate of 50 per cent to 60 per cent for those with stage 4 cancer. 

Mr Choy started chemotherapy and radiation therapy just a week after being diagnosed. 

While he is currently cancer-free, he has some side effects from the treatment, such as weak throat muscles, which can affect swallowing. 

“If my cancer had been detected earlier, we may have been able to optimise the treatment to minimise the side effects,” he said.