Blood test for early detection of gastric cancer being evaluated for use in primary healthcare
SINGAPORE – A blood test that can detect gastric cancer in its early stages has been developed and is currently being evaluated for use in hospitals and clinics, said the National University Health System (NUHS) on Friday (Oct 23).
In Singapore, gastric cancer is the fifth cause of cancer deaths in men and the sixth in women, claiming around 300 lives yearly.
It is the third leading cause of cancer deaths worldwide, as it is often detected at the later stages, making it difficult to treat.
Gastric cancer is usually diagnosed through endoscopy, a procedure perceived to be expensive and invasive, as it involves inserting a thin tube with a camera into the patient’s mouth and all the way down to the stomach.
An endoscopy costs around $200 to $800 with medical subsidy, according to the Ministry of Health’s website.
On the other hand, using the blood test would be more cost-effective – it would be priced at under $200 at public hospitals. The test is also non-invasive, and can encourage higher uptake among the public for early detection of the cancer and reduce reliance on endoscopy.
It would take around three hours to run in a clinical lab and can deliver results to the patient’s doctor within a week.
The project to develop the new blood test began in 2012. It was led by Professor Jimmy So, head and senior consultant with the National University Hospital’s (NUH) division of general surgery (upper gastrointestinal surgery); Professor Yeoh Khay Guan, senior consultant with the NUH’s division of gastroenterology and hepatology; and Associate Professor Too Heng-Phon from the National University of Singapore Yong Loo Lin School of Medicine’s department of biochemistry.
The team also included clinicians and scientists from NUHS; the Bioprocessing Technology Institute (BTI) of the Agency for Science, Technology and Research (A*Star); national platform Diagnostics Development Hub; and MiRXES, a Singapore-headquartered molecular diagnostic company that was spun off from A*Star’s BTI.
The blood test can detect 87 per cent of all gastric cancers, including 87.5 per cent of stage one cancers, by looking out for patterns of microRNA – a type of gene in the blood sample.
The results were found to be more accurate compared with conventional blood tests for gastric cancer, and were highly sensitive across age groups, genders, ethnicities and tumour stages.
Using a panel of 12 microRNA biomarkers that can differentiate gastric cancer patients from normal patients with an accuracy of more than 92 per cent, an initial test kit was manufactured in 2012.
From 2013 to 2018, the test kit was validated among some 5,000 subjects from Singapore, and received approval from the Health Sciences Authority last year.
Prof So said: “The majority of gastric cancer patients are diagnosed at advanced stages, for which the five-year survival rate is lower than 5 per cent. Early detecting is thus key to reducing death from gastric cancer. To bring about a meaningful fall in the gastric cancer mortality rate, an effective strategy that would detect gastric cancer early so as to enable prompt intervention is required.”
He added: “This non-invasive blood test is a breakthrough in gastric cancer diagnosis and it may potentially be used as an effective screening test for the early diagnosis of gastric cancer.”
As it costs less than endoscopy, the test could potentially be used as part of the national screening programme of gastric cancer in high-risk groups.
Patients who have positive 12-microRNA test results will then be recommended to go for endoscopy.
Prof Too, however, emphasised that the test does not replace endoscopy, and instead provides an option to patients who may not be keen on initial endoscopic screening.
Instead, it “adds to the current cancer detection tool armamentarium”, and provides the public with access to better healthcare through its convenience and non-invasiveness.