Four major medical institutions, led by the National Cancer Centre Singapore (NCCS), are collaborating to carry out a clinical trial which may lead to the development of a new treatment strategy to better fight one of Singapore's top killer cancers.

By combining a 10-year-old treatment and one so new it is still being studied, doctors are hoping to help their patients better fight liver cancer.

This approach is the first of its kind in the world.

This new liver cancer trial was started in December 2016 and it aims to recruit 40 people for the trial.

The institutions involved are NCCS, Singapore General Hospital (SGH), the Genome Institute of Singapore and the Singapore Immunology Network.

An option for people with intermediate-stage liver cancer - meaning that surgery can no longer be done - is to undergo a treatment known as Y90 radioembolisation.

During this treatment, radiation is delivered directly to the tumour to kill cancer cells.

As these cells die, explained SGH's adjunct associate professor David Ng, it is believed that they release a substance that also stimulates the immune system.

"The immune cells then attack the tumour cells as well," said Prof Ng, who heads the hospital's department of nuclear medicine and positron emission tomography.

Even then, the immune system sometimes has trouble detecting the tumour cells.

This is where the new drug, known as Nivolumab, comes in.

In the words of Dr Choo Su Pin, a senior consultant medical oncologist at the NCCS and Lead Principal Investigator for this study, it "wakes up" the immune system.

"Basically, your body recognises the cancer cells as bad, and eliminates them," she said.

Thus, the aim of the trial is to show that nivolumab can enhance the effects of radioembolisation in liver cancer and further improve outcomes for patients.

"Nivolumab has shown some initial promising activity in advanced liver cancer and studies are ongoing. We plan to study whether nivolumab may help to further enhance the efficacy of (Y90) radioembolisation. If proven so, this will change the way we treat liver cancers."

In Singapore, liver cancer ranks among the top five causes of cancer deaths, with around 2,500 people dying of it between 2010 and 2014.

The new trial is open to people suitable for the Y90 radioembolisation treatment, or around 30 per cent of liver cancer patients.

Those who take part in the trial will first undergo the Y90 treatment.

Three weeks later, they will receive a dose of nivolumab every fortnight. They will be closely monitored throughout.

People who are interested to participate in the trial may contact NCCS at chong.hui.shan@nccs.com.sg.