Scientists are one step closer to being able to predict a woman’s individual risk of breast cancer more effectively, something Josie Dietrich says could have helped her fulfil her dream of having a second child.
The 43-year-old Brisbane woman was diagnosed with an aggressive form of breast cancer eight years ago and while she survived the disease, she lives every day with chronic pain.
“From cancer I had both my breasts removed, my ovaries removed, my womb removed, my cervix removed,” she said.
“I am on a drug every day still eight years later … I have massive menopausal issues that also have an effect on bone strength.”
On Tuesday, researchers involved in the world’s biggest genetic study of breast cancer announced they had discovered 72 genetic variants that put women at risk of the disease, almost doubling what researchers knew before.
Ms Dietrich said the discovery, published in Nature and Nature Genetics, was “superb”.
“If I knew I had a high chance (of getting breast cancer) … or if there were other indicators then I would have done something about it,” she said.
“If you could stop that (cancer) from ever happening to you that would change my quality of life and it would have meant I could have had a second child.
“I wasn’t able to have another child after diagnosis, so it completely changed my world and if there was a chance to stop that it would have been really good.”
Researchers collected and analysed data of 275,000 women, half of whom had breast cancer, from around the globe with the aim to evaluate why some women were more at risk than others of developing the disease.
QIMR Berghofer’s Professor Georgia Chenevix-Trench, who helped co-lead the international collaboration, said the discovery almost doubled what researchers already knew about existing genetic markers.
“We knew about 100 before, it is a big contribution but probably more important than the number is the methods we developed,” she said.
“We have developed new methods to try and predict what these genetic variants are doing and what genes they are acting on.
“Nearly all of those genes are ones that we had no idea played a role in breast cancer risk before so it really opened our eyes to understanding the causes of breast cancer.”
Breast cancer is caused by complex interactions between genetic variants and environmental factors.
About 70 per cent of breast cancer responds to the oestrogen hormone, which helps the tumour to grow.
In 2017, it is estimated that 17,586 women and 144 men will be diagnosed with breast cancer, according to Breast Cancer Network Australia.
The study uncovered 65 genetic variants that predispose women to the overall risk of the disease and seven variants that predispose women to oestrogen-receptor negative breast cancer, which does not respond to tamoxifen, a treatment used to reduce the risk of breast cancer.
Professor Chenevix-Trench said the discovery pushed researchers one step closer to being able to develop targeted risk reduction medications.
“We may be able to develop palatable, safe, non-toxic methods for reducing breast cancer risk, particularly women who are at a high genetic risk,” she said.
“Many women are offered mammogram screenings when they are middle-aged, but if we know a woman has genetic markers that place her at higher risk of breast cancer, we can recommend more intensive screening at a younger age.
“There isn’t a clinical test available right now to measure these variants but this knowledge at least puts us in a better position to develop that clinical test.”
The studies involved collaborators from 300 different institutions, including the University of Cambridge, University Laval in Quebec and Harvard TH Chan School of Public Health.