Researchers found the drug denosumab stopped the growth of cells that are a precursor to breast cancer in women with a BRCA1 gene mutation.
In a study published the journal Nature Medicine, researchers reveal how the drug denosumab halted the growth of pre-cancerous cells in breast tissue of women with a faulty BRCA1 gene.
Women with a BRCA1 gene mutation are at significantly greater risk for breast and ovarian cancers; around 55-65 percent of women with such a mutation will develop the disease by the age of 70, according to the National Cancer Institute, compared with 12 percent of those in the general population.
At present, the only way for women with a BRCA1 mutation to significantly reduce their risk of breast and ovarian cancers is to opt for a mastectomy - the surgical removal of one or both breasts - or an oophorectomy - the removal of the ovaries.
But in this latest study, Prof. Geoff Lindeman, of the Walter and Eliza Hall Institute of Medical Research (WEHI), Australia, and colleagues show promise for a non-surgical alternative.
Uncovering the 'holy grail' of cancer research
To reach their findings, the team analyzed a number of breast tissue samples from women with and without a BRCA1 mutation.
- This year, around 246,660 new cases of invasive breast cancer will be diagnosed in the U.S.
- Around 40,450 women will die from breast cancer in 2016
- There are currently more than 2.8 million breast cancer survivors in the U.S.
From this, they identified cells in the breast tissue from women with a BRCA1 mutation that act as a precursor to breast cancer.
"These cells proliferated rapidly, and were susceptible to damage to their DNA - both factors that help them transition towards cancer," explains study co-author Prof. Emma Nolan, of the Department of Medical Biology at The University of Melbourne, Australia.
What is more, the researchers found that a protein called RANK acted as a marker for these pre-cancerous cells - a finding that excited the team, given that there are already drugs in clinical use that target and block the RANK pathways.
As such, the researchers decided to investigate how one of these drugs - known as RANK ligand inhibitors - would affect the progression of pre-cancerous breast cells.
They focused on a medication called denosumab, which is currently used to treat osteoporosis and bone cancers, including breast cancers that have spread to the bone.
On applying denosumab to BRCA1-mutated breast tissue, they found it deactivated the growth activity of pre-cancerous cells. What is more, the drug halted breast cancer development in a BRCA1-deficient mouse model.
Overall, the researchers say their findings indicate that targeting the RANK pathway may be an effective strategy to reduce breast cancer risk in women with a BRCA1 mutation.
"By thoroughly dissecting how normal breast tissue develops, we have been able to pinpoint the precise cells that are the culprits in cancer formation.
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."
Study co-author Prof. Jane Visvader, WEHI
The authors say that a clinical trial is already underway to further investigate the breast cancer-preventing potential of RANK-inhibiting drugs.