Genetic testing advances help women with high risk of breast cancer avoid surgery

By: Vittoria D’Alessio, Horizon: The EU Research & Innovation Magazine

From: medicalxpress.com

Researchers are discovering new genes linked to breast cancer and refining evaluation of risk to help spare women from life-changing surgery.

Celebrity actress Jolie made headlines in 2013 when she underwent radical breast surgery after genetic testing revealed she carried a gene—BRCA1—that significantly increased her odds of developing breast and/or ovarian cancer.

Fast forward a decade and eight more genes known to raise a woman’s susceptibility to breast cancer have been discovered. Among these are BRCA2, which also greatly increases the chances of developing breast cancer, and four genes discovered by BRIDGES, an international research project.

Thanks in large part to groundbreaking work by researchers, prophylactic surgery is no longer seen as inevitable for a woman to stay healthy if she carries a gene that increases her risk of breast cancer.

In parallel to these discoveries, medical understanding of risk—the likelihood of a woman developing breast cancer if she carries specific mutations—has also evolved significantly.

Avoiding surgery where possible

Greater clarity around the level of risk and the treatment options available is welcomed by women‘s cancer support groups.

“The ideal outcome of genetic screening is for women to get an accurate picture of their risk and be offered a personalized approach to tumor prevention,” said Marzia Zambon, executive director of Europa Donna, Europe’s largest breast cancer advocacy group.

“We’re pushing for genetic testing to always be done with the professional guidance of a genetic counselor. If testing isn’t done right, it can cause a lot of stress and an unnecessary escalation of treatment.”

Researchers involved in BRIDGES and B-CAST—another research initiative—have made huge advances in showing how both genes, lifestyle and environmental factors influence the risk of breast cancer. These non-genetic factors include a woman’s exposure to pollution, excess body weight, breast tissue density, low physical activity, alcohol consumption, exposure to birth control and other hormones, and the number of children born.

“Until recently, genetic testing could identify women carrying genes linked to breast cancer, but estimates of the risk these women were facing were quite imprecise,” said Professor Peter Devilee, BRIDGES research coordinator and cancer geneticist at Leiden University in the Netherlands. This matters because imprecise risk evaluation can result in inaccurate treatment advice.

“Women with a family history of breast cancer are being referred to labs for genetic testing, and mutations are being identified, but if you can’t translate a result into a fairly precise breast cancer risk, it can lead to improper risk management advice. We wanted to help clinics interpret results properly.”