• Posted February 20, 2024

Preventive Mastectomies May Save Lives of Women With Breast Cancer Genes

Women who carry certain mutations in their BRCA1 or BRCA2 genes know they are at heightened odds for breast cancer.

Now, Canadian research suggests that for some patients a "risk-reducing" preventive mastectomy may cut the odds of dying from breast cancer later.

“The decision to have a risk-reducing mastectomy is often difficult for a woman to make, and the more evidence we are able to provide them with when they are making that decision, the more informed their care plan will be,” said study lead author Kelly Metcalfe, of the University of Toronto.

Her team published its findings recently in the British Journal of Cancer.

It's well-known that carrying certain variants of the BRCA1 or BRCA2 gene raises a woman's lifetime odds for breast cancer by 80%, the researchers said.

Having breasts removed can prevent the disease by 90% in these women, studies have shown. In Canada, 30% of BRCA1 or BRCA2 gene carriers at higher odds for breast cancer opt for the surgery, Metcalfe's group noted.

But will this drastic surgery really lower a woman's odds for fatal breast cancer?

In the study, the research team looked at data on over 1,600 women from nine countries. All carried BRCA genes tied to heightened breast cancer risk, and half of the women underwent risk-reducing mastectomies.

At six years of follow up, there were 20 cases of breast cancer and two deaths in women who had opted for risk-reducing mastectomy, the study found.

That's far less than the 100 breast cancer cases and seven deaths among women with the BRCA genes who had not opted for the procedure.

Overall, risk-reducing mastectomy cut risks of getting breast cancer by 80%, the study found. The odds of dying from breast cancer 15 years after the mastectomy was just 1%.

Metcalfe believes more studies are needed that can track women's outcomes even longer.

“Right now, we have good screening in place for breast cancer, including breast MRI, so surgery is only offered as an option, not a recommendation,” Metcalfe said in a university news release. “But with more studies being conducted to assess women's trajectory and risk factors following [risk-reducing mastectomy], we will know whether these guidelines need to be changed in the future.”

More information

Find out more about the BRCA genes at the Susan B. Komen Foundation.

SOURCE: University of Toronto, news release, Feb. 16, 2024