Victorian researchers have successfully used two drugs to give hope to women with advanced breast cancer.

For Victorian Julie Baulch, a breakthrough drug trial to treat her breast cancer has given her a new lease on life.

Ms Baulch, 62, has been taking part of a Melbourne-based trial for two years that joins venetoclax, a drug which has shown promise in the treatment of chronic leukaemia, with tamoxifen, a therapy used to treat breast cancer.

She had been diagnosed with a large 10cm tumour just before her 60th birthday in 2015, with the option of a mastectomy on the table.

But Ms Baulch was eligible to take part in a world-first new trial that combined the two cancer drugs for treatment, thanks to breast cancer researchers at The Royal Melbourne Hospital and Peter MacCallum Cancer Centre.

"Initially, they were deciding whether to give me a mastectomy and luckily they decided I was suitable for the trial," she said.

While the drugs made her a little unwell at first, it was better than more intrusive options, she said.

Her tumour, picked up in a mammogram, has significantly reduced in up to five months to being almost undetectable since using the combined drugs, she said.

"I am feeling optimistic, just take it one day at a time. We hope it keeps as is, stable, and one day they can get rid of it forever," she said.

Ms Baulch is one of 42 women with the disease who took part in the study over the last three years, with 75 per cent having an overall improvement.

Medical oncologist Sheau Wen Lok with the Royal Melbourne's Hospital said on Friday that the treatment gave hope to cancer patients.

"We are excited by these findings as they do offer hope. At the same time we understand we will need to perform further studies to work out what the role is in the clinic," Dr Lok said.

The study is based on a finding from the Walter and Eliza Hall Institute of Medical Research which tested breast cancer cells with this mix of drugs and found they worked well together.

It is the first time venetoclax has been used on solid tumours and could be a breakthrough in the cancer treatment, Dr Lok added.

"Venetoclax is a relatively new drug and in the last few years it has been used to treat patients with blood cancers ... and we have seen some remarkable results with that," Dr Lok said, adding it is on that basis researchers hope it will help fighting breast cancer.