With her mother and grandmother lost to cancer, the only option for Kylie Gellie was to remove her breasts, fallopian tubes and ovaries.
The surgeries were dramatic and invasive, things she hopes her two daughters - Sienna, 3, and Jasmine, 9 - won't face as young women. 
Promising research published in Nature Medicine today has found an existing drug may prevent breast cancer in the estimated one in 400 women carrying the faulty BRCA1 gene.
The team, led by Australian researchers, has found injections of an inhibitor reduced the proliferation of pre-cancerous cells in BRCA1 breast tissue in mice and three Melbourne women carrying the gene mutation.
Now, the first international human trial is expected to begin within two years.
It could mean cancer prevention for the high risk group of carriers, which includes Hollywood actress Angelina Jolie Pitt, would be reduced to a handful of injections.
The study was led by professors Geoff Lindeman and Jane Visvader from Melbourne's Walter and Eliza Hall Institute, and PhD student Emma Nolan.
They used healthy breast tissue donated by women such as Ms Gellie before undergoing surgery to pinpoint cells that give rise to breast cancer in faulty BRCA1 genes.
The researchers discovered these rogue cells could be identified by a marker protein called RANK, a breakthrough that turned their studies towards an existing drug called denosumab.
Denosumab is used as an inhibitor of RANK in osteoporosis and breast cancer that has moved to the bone. When they used the drug on the donated breast tissue, the pre-cancerous rogue cells stopped dividing, or were "switched off".
"By blocking the activity of this RANK receptor we could switch off the proliferation of these cells that are ultimately predisposed to becoming cancerous," Professor Visvader said. Further tests of the inhibitor on BRCA1 mice found two-thirds of them did not go on to develop tumours, the research shows.
"It is very exciting to think that we may be on the path to the 'holy grail' of cancer research, devising a way to prevent this type of breast cancer in women at high genetic risk," Professor Visvader said.
Professor Lindeman, who is also a medical oncologist at the Royal Melbourne Hospital, said a pilot study of the drug on three human BRCA1 carriers in Melbourne had also shown a significant reduction in the number of dividing cells.
The women had been given a short series of injections.
"The hope would be that this would either prevent or delay tumour development in BRCA1 mutation carriers," Professor Lindeman said. "Women who have BRCA1 mutations have few options ... in terms of prevention. The only thing that's really proven is mastectomy, which is highly effective but invasive." He said the next step - large clinical trials - would likely take another decade.
If found to have merit, the injection method would come in time for Ms Gellie's daughters. "The women in my lineage don't survive," she said. "My girls are nine and three and I think that they most probably carry this gene as well because it is very strong in my family.
"I'm the first generation who will survive and my next step now is to help my girls.   Maybe they don't have to go through such drastic measures as I did or maybe it can buy them some time."