A significant step in reducing the risk of women who carry a deadly cancer gene from developing the disease has been made by researchers at Queen's University.
Hailed as a "potential breakthrough" the new research indicates that drugs – not surgery – could help carriers of the BRCA1 gene from developing ovarian and breast cancer.
Clinical trials are expected to be carried out in Northern Ireland in the next 12 months, but women who carry the gene have welcomed the news as "a major step".
Currently around one in 1,000 women in the UK carries what is known as a BRCA1 mutation. It affects several hundred women in Northern Ireland.
Until now preventive surgery –a mastectomy, the removal of breasts, and oophorectomy, the removal of the ovaries – has been the only way of reducing the risk.
Breast cancer is the most common type of cancer in women in the province with at least one in eight being diagnosed with the disease.
And ovarian cancer claims the lives of around 119 women here annually.
But the four-year research by Dr Kienan Savage and Professor Paul Harkin at the Centre for Cancer Research and Cell Biology (CCRCB) proves there is a direct link between high levels of oestrogen and DNA damage, which causes cancer in the breasts and ovaries.
They found that cells of women with the BRCA1 mutation cannot effectively fight the very high levels of oestrogen that exist in all women's breasts and ovaries.
This leaves them vulnerable to DNA damage.
What this means is that drugs already available that "turn off oestrogen production" could be used as a preventative treatment.
The Belfast scientists say that "in theory" they could use these drugs to chemically reduce oestrogen production in women, which could stop the need for irreversible surgery.
The scientists believe this means such treatments would also open up the possibility of some women – who might otherwise have had to have ovaries surgically removed – still being able to have children.
While a direct link between oestrogen, breast/ovarian cancer and the BRCA1 mutation has been suspected by the scientific community for years, it has not been proven until now.
It is the same condition that prompted Oscar-winning actress Angelina Jolie to undergo a double mastectomy.
It was recently reported she was set to undergo further surgery to remove her ovaries.
Those with the gene have up to an 85% risk of developing breast cancer, and up to 40% risk of developing ovarian cancer.
Experts at QUB have described it as the first "credible evidence that oestrogen is driving cancer in women with a BRCA1 gene mutation".
Dr Savage, who led the research, said the discovery was "very significant" in the management of women with the BRCA1 gene mutation.
"It's the first really credible evidence that oestrogen is driving cancer in women with a BRCA1 gene mutation," he said.
"Because of this discovery we now have the opportunity to propose an alternative treatment to surgery.
"It also opens up the possibility of pausing treatment for a period in order for women to have children, if desired," he explained.
"What also makes this exciting is that there are drugs already on the market which turn off oestrogen production.
"In theory, we could use these drugs to chemically reduce oestrogen production in women which could negate the need for irreversible surgery."
The Queen's-led research was carried out with funding from Cancer Focus NI and Cancer Research UK. It is featured in the latest edition of the US-based journal Cancer Research.
Professor David Waugh, director of the CCRCB, said the breakthrough by researchers was great news for women with the BRCA1 gene and the global cancer research community as a whole.
"It is pivotal in that it reveals more about the mechanisms behind breast and ovarian cancer," he said.
Roisin Foster, chief executive of Cancer Focus Northern Ireland, also welcomed the breakthrough.
"Cancer Focus is delighted to fund this groundbreaking research into breast cancer, which has the potential in the forseeable future to benefit women all over the world," she said.
What Queen’s scientists discovered
* Cells of women with the BRCA1 gene cannot effectively fight very high levels of oestrogen that exist in all women’s breasts and ovaries. This leaves them vulnerable to DNA damage.
QUB scientists believe drugs which are already available that “turn off oestrogen production” could be used as a preventative treatment.
* The researchers are currently seeking funding to launch clinical trials and hope to do so within 12 months.
It is envisaged that, in the first instance, a small control trial will be carried out using a combination of two drugs on 12 women for a period of three months, using biopsy, blood and urine samples to track DNA damage. Those with the gene have up to an 85% risk of developing breast cancer and up to 40% risk of developing ovarian cancer.
The ovary-removal procedure, called an oophorectomy, will lower the risk of ovarian cancer by 80%-90% by reducing the amount of oestrogen and progesterone circulating in the body.
* There are multiple options for these people and each individual should consider what is best for them.
Options include: extra screening with mammography and/or MRI scans, or potentially risk-reducing surgery such as a mastectomy.