The 70-year-old Grease star joined experts on Monday to open the Victorian Comprehensive Cancer Centre Research Conference 2019, which will discuss a range of treatment elements including nursing, palliative care, research, clinical trials, and patient support.

Newton-John was diagnosed with breast cancer in 1992 and underwent surgery and chemotherapy.

She subsequently got involved with fundraising and Melbourne's Alfred Health later established the Olivia Newton-John Cancer Research Institute.

The institute encourages music and art as sidelines to treatment, which Newton-John says were valuable tools in her own rehabilitation.

"I got to experience that and realise how incredibly important it is psychologically when you're going through a cancer diagnosis and treatment to have this outside support and creativity and things that inspire you to get well," she told Monday's audience.

Newton John also repeated her much-publicised praise for medicinal cannabis.

"Cannabis really helped me. I was able to wean myself off the morphine with cannabis," she said.

More research was needed into the use of cannabis, but Newton-John said it helped her ease pain and sleep.

"The proof is in the pudding and I'm the pudding."

Australian Associated Press