At the age of 33, after experiencing symptoms, "similar to depression," Ms Malamai was diagnosed with a large brain tumour.

"I had never heard of brain cancer. Those two words together just sound awful.," Ms Malamai said.

"I was given three months to live."

As the biggest cancer killer of Australians under the age of 40, brain cancer kills more children in Australia than any other disease.

After surgery three days later, surgeons told Ms Malamai there was nothing more they could do.

"That day waking up in the ICU was the worst day of my life. It hit me that I was probably going to die and my kids were so little," she said.

Ms Malamai's sister got her an appointment with renowned neurosurgeon Dr Charlie Teo, who performed further surgery three months later.

"He removed 97 per cent of the tumour, but the disease is incurable so even with successful surgery it's expected to come back within 18 months," she said.

"There's only a 5 per cent survival rate past 18 months."

Seven years later, Ms Malamai is well and truly in the 5 per cent. Although she still has symptoms, she said she feels, "blessed to be here".

"I met four other patients with the same disease, and they all died. That was so devastating, watching people die from the disease you've got," Malamai said.

This Sunday, Ms Malamai will be joined by fellow ambassadors Wallaby captain and Brumby Stephen Moore and Wallaroo Louise Burrows in the Walk4BrainCancer at Mt Stromlo.

Unlike some cancers with higher survival rates, little is known by the public about brain cancer, which means less funding for research.

"Everyone who's diagnosed is told they won't have much time, and the very last thing you want to do is go out and talk about it. You just want to stay at home with your family and closet yourself off from the world," Ms Malamai said.

"But the only way to take an incurable disease to curable is money."

Event organiser Amanda Finton said the walk is a two kilometre flat, grass track which means everyone can do it, including those with prams or in wheelchairs

"While we have to understand the devastation of the disease, the day is about hope to bring awareness and raise funds," said Ms Finton.

Walk4BrainCancer is on Sunday November 30 at Stromlo Forest from 9.30am. Register at walk4braincancer.com.au or on the day.