It was earlier this year when the 24-year-old nursing graduate's identical twin sister Winnie – also a nurse – first noticed her tummy growing. Ms Lau and her twin moved to Canberra from Hong Kong seven years ago.

"At that time, I didn't really notice the difference until April when it just kept getting bigger and some of my clothes didn't fit anymore," Ms Lau said.

"It was like I was six, seven months pregnant."

Doctors suspected Ms Lau had a tumour but thought it would be benign.

The twins' older sister May, who is also a nurse and lives in Adelaide, knew of an oncologist specialising in rare tumours and Ms Lau flew to South Australia, desperate for answers.

She had surgery in May and Dr Susan Neuhaus, a surgical oncologist at the Royal Adelaide Hospital, removed the "porridge-like" form and sent it for testing.

"During the operation, I lost eight litres of blood so it was very frightening," she said.

"The doctors told my family that if the bleeding didn't stop, that's it for her and that was the moment my boyfriend decided to propose because he didn't want to miss anything and to have regrets in the future."

Ms Lau had another operation the next day. It went well although she spent another two days in ICU.

A few weeks later, tests confirmed Ms Lau had extra-uterine endometrial stromal sarcoma, an extremely rare cancer outside her uterus.

"When they told me, I thought I had just been misdiagnosed because it's so rare... in my mind, I kept thinking it's not cancer. Even going through my first few cycles of my chemo treatment, I still had that thought in my mind," she said.

In a happy moment among the hardship, Ms Lau and her fiancé Sherman married in July, weeks before she began treatment in August.

She expect to finish chemotherapy by December and hopes to return to work as a nurse by February.

Ms Lau said she and Winnie – who used to be nicknamed Chip and Dale when they were younger – were extremely close.

"The way she has supported me through prayer has been so useful," she said.

"She's been so great while I've been having my treatment and she has also been financially supporting me."

Ms Lau also praised the ACT Youth Cancer Services for their support

"It would be a huge strain without their help," she said.

They helped buy her a wig which she said helped restore her confidence after losing her hair. They also connected her with financial services to help with expenses while she is unable to work and cover the cost of two medications she requires which are not PBS-listed.

In NSW and ACT, Youth Cancer Services provided specialist services to 737 patients between 2013 and 2014.

CanTeen held an event at Parliament House on Tuesday to highlight the achievements of YCS which provides specialist medical and psychological care to 15 to 25-year-olds with cancer.

It is run nationally by CanTeen with Australian government funding.

"Primarily we want the politicians to understand that their funding is doing some fantastic work, some really important work in terms of patient care but also let me know that we've got some work ahead of us still to reach all the patients but we need that ongoing support of the federal government," CanTeen chief executive Peter Orchard said.

Mr Orchard said young people with cancer had unique needs, highlighting the importance of specialised services like YCS.

Last year, 55 per cent of newly diagnosed patients were treated through YCS – but CanTeen wants to see that number increased.

"The real complexity, particularly with this age range 15 to 25, is that you get this straddling of paediatric cancers and adult-type cancers," he said.

About 20 young people are expected to be diagnosed with cancer in the ACT each year.

For more information, visit: canteen.org.au/how-we-help/youth-cancer-services/early-warning-signs-of-cancer/.