When Helen Easton gazes lovingly into her great-granddaughter Halle’s eyes, she knows how close she came to never seeing them at all…

The 76-year-old woman was diagnosed with a malignant brain tumour in 2011 and given six months to live.

But thanks to a world-first clinical trial in Brisbane, Mrs Easton has been able to beat the notoriously aggressive brain cancer glioblastoma multiforme (GBM).

Mrs Easton joined the QIMR Berghofer Medical Research Institute trial in 2012 after already enduring two surgeries and seeing her cancer return.

Study leader Professor Rajiv Khanna says despite only 10 per cent of patients usually surviving more than five years, Mrs Easton was in the majority of patients now exceeding expectations.

The trial trains immune system cells to attack cytomegalovirus (CMV) cells found within the brain tumour.

It works on half the population, given that about one in two Australians have the virus, despite usually showing no symptoms.

Prof Khanna says the process, called immunotherapy, involves modifying patients’ T-cells in a laboratory and putting them back into their bodies.

“So basically it’s like taking a lay person and then training that person to become an army person,” he told reporters.

“It’s like taking those cells and infusing them back into the patient to be able to very specifically target the cancer cells.”

Prof Khanna said the process had little negative side-effects, which he considered the `Holy Grail’ for cancer treatment.

One moment, Mrs Easton was watching a cricket match and started to feel ill.

Doctors were soon telling her to put her affairs in order. Her grandson Daniel Reeves convinced her to take part in the trial during a hospital visit.

“Daniel just came up and said to me: `Nan, you’ve got fight it, we’re going to give you a great-grandchild,” she said.

“So I had to fight it because I wanted to see that great-grandchild and now we have Halle and she’s beautiful.”

Prof Khanna’s research was published on Monday in the prestigious US journal Cancer Research.