A 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.
The drug is currently used to treat osteoporosis and will soon be tested in human clinical trials.
If proven right, it could allow women with a high risk of the disease an option to delay or prevent it without having a mastectomy.
A sobering statistic is that women with the BRCA1 gene have a 65 per cent chance of developing the disease – and there aren’t many preventative measures out there.
Angelina Jolie made international headlines in 2013 by announcing that she had undergone a preventative double mastectomy after becoming aware of her family history with the BRCA1 gene.
The Age reports that 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 before undergoing surgery to pinpoint cells that give rise to breast cancer in faulty BRCA1 genes.
The researchers found 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 tells The Age.
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 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 adds.
“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.”