New secret weapon for breast cancer

Breast-cancer prevention has a new secret weapon, following the  world’s biggest ever genetic study of breast cancer.

Analysing data from 275,000 women globally, researchers discovered 72 new genetic variants that put women at higher risk of the disease. This knowledge will allow doctors to identify women at risk at a younger age and to put in place screenings and treatments to eliminate the risk.

Co-led by Australian researchers at the IMR Berghofer Medical Research Institute in Queensland, the study found 65 genetic variants that predispose women to overall risk of breast cancer.

Professor Georgia Chenevix-Trench, from the institute, said a further seven genetic variants were discovered that predispose women specifically to oestrogen-receptor negative breast cancer, which often leads to poorer health outcomes because it does not respond to drugs like tamoxifen.

Around 70% of all breast cancer is oestrogen-receptor positive, which means the cancer responds to the hormone oestrogen and helps the tumour to grow. A smaller number of breast cancer cases are oestrogen-receptor negative, so they do not respond to oestrogen but respond to other mechanisms.

“Many women are offered mammogram screening 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,” Professor Chenevix-Trench said.

“This work helps us to understand why some women are more at risk of developing breast cancer than others and what genetic markers we should be looking for in order to assess that risk.

“Our hope is that in future we will be able to test for these genetic variants in order to inform preventative approaches and treatment for women who may be at a higher risk of breast cancer.”

QIMR Berghofer senior researcher Dr Jonathan Beesley said that one of the main findings was that scientists can now predict which neighbouring genes the risk variants might act on.

“We think that this ability to pinpoint the genes associated with risk of breast cancer will eventually enable us to develop more effective screening interventions and even risk-reduction medications and treatments.”

The research was a collaboration across 300 different institutions globally. The findings were published recently in the journals Nature and Nature Genetics.

Image credit: ©stock.adobe.com/au/Stepan Kapl