Women who suffer from a gene mutation that makes them highly susceptible to breast cancer may no longer need to undertake preventive mastectomies after research identified a prophylactic drug.
A fault in a gene known as BRCA1 gives women a risk of developing breast cancer by the age of 70 of between 65 and 85 per cent.
In 2013 Angelina Jolie, the actress and UN special envoy, chose to have a voluntary double mastectomy after being told that she had the mutation, which affects less than 1 per cent of women.
Every year many other women make the same decision to undergo surgery rather than risk contracting the disease.
Drug companies have been working to find a treatment that reduces the risk in those who already know there is a high chance they will get breast cancer, so that they can avoid surgery.
A team of Australian scientists has identified a strong contender. Tests in a laboratory showed that a drug used to treat osteoporosis may also block the processes involved in the early stages of breast cancer in women with the BRCA1 mutation.
However, scientists cautioned that the work, published in the journal Nature Medicine, was still at a very early stage and may yet prove to be a false hope. Denosumab inhibits a protein involved in bone health which was also found to mark out pre-cancerous cells. By taking breast tissue from women with the faulty BRCA1 gene, the researchers found that in the laboratory this drug stopped breast cancer development.
They are now carrying out a trial in patients to see if the same holds true.
“By thoroughly dissecting how normal breast tissue develops, we have been able to pinpoint the precise cells that are the culprits in cancer formation,” said Professor Jane Visvader from the Walter and Eliza Hall Institute in Melbourne.
“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.”
Other scientists welcomed the research. “Today’s findings reveal an exciting prospect — that an existing drug may hold the key to preventing women with a faulty BRCA1 gene developing breast cancer,” said Samia al Qadhi, the chief executive of Breast Cancer Care. “This means that, in future, women living with an inherited higher risk could have another treatment option and the chance to avoid invasive and often distressing surgery, such as double mastectomies.
“However, there remain many unanswered questions: we don’t know how long people would need to have the drug or the impact of side-effects. The next step is to explore the promise of this treatment through larger clinical trials.”
Professor Peter Barrett-Lee, a clinical oncologist at the Velindre NHS Trust in Wales, said that it was “very interesting work” but he added: “The observations would need to be tested in patients and this possible approach will be quite a few years in the making, even if it works.”
The “Angelina Jolie” effect has been credited with causing a sharp increase in women undergoing preventive double mastectomies. Researchers found that the number had more than doubled since she announced she had had the procedure.