Breast cancer gene mutation linked to survival after double mastectomy

by Thomas R. Collins: Women who are diagnosed with early stage breast cancer who also carry a mutation on the BRCA breast cancer gene are less likely to die following  a double mastectomy than women who have one breast removed, researchers reported online in the BMJ/British Journal of Medicine on February 11, 2014.

As background, the authors noted that women with a BRCA1 or BRCA2 gene mutation have a lifetime breast cancer risk of 60 – 70%. When diagnosed with breast cancer, they have a high risk of developing a second primary breast cancer. To date, there has been little information on the long-term survival of women with either gene who are treated for breast cancer.

Researchers from the US and Canada reviewed data on the twenty year survival experience of 390 women, from 290 different families, with early-stage breast cancer, who were diagnosed from 1975 to 2009. The women were either carriers or were likely to be carriers of the BRCA1 or BRCA2 gene. They had been treated with single or double mastectomy.

Forty-four subjects were initially treated with bilateral (double) mastectomy, and 346 were initially treated with unilateral (single) mastectomy.

Of those undergoing unilateral mastectomy, 137 had the other breast removed later (contralateral mastectomy).

During the 20 year follow-up period, 79 women died of breast cancer, 18 from the bilateral mastectomy group and 61 from the unilateral mastectomy group. Having both breasts removed was associated with a significant (48%) reduction in breast cancer death compared to removal of one breast.

Based on these findings, the researchers estimated that, of 100 women treated with double mastectomy, 87 will be alive at 20 years compared with 66 of 100 women treated with single mastectomy.

The authors concluded that bilateral mastectomy should be discussed as an option for young women with a BRCA mutation and early onset breast cancer.

In an accompanying editorial, Karin Michels, PhD, ScD, from Harvard University Medical School in Boston, Massachusetts said although the study suggests a significant reduction in breast cancer related deaths with a double mastectomy, “larger studies tackling this issue are needed and will undoubtedly be generated in the years to come.”  She added that breasts are an “essential part of women’s identity, sexuality, and self- perception” and that no statistics can make the decision on whether a woman will opt to undergo a double mastectomy.