Concern About Breast Cancer Genetic Risk Drives Bilateral Mastectomy Decisions

A surprisingly high proportion of young women diagnosed with breast cancer who said “concern about genetic risk influenced their treatment decisions” opted for bilateral mastectomy, despite testing negative for the BRCA mutation, data from an ongoing prospective cohort study have found.¹

While this decision suggests women may wish to have peace of mind, “it might also suggest a need for better communication of the relatively low risk of contralateral breast cancer among women who are noncarriers, that this risk has been decreasing in recent years, and that bilateral mastectomy is not associated with improved survival,” wrote Ann H. Partridge, MD, MPH, of the Dana-Farber Cancer Institute in Boston, MA, and coauthors in JAMA Oncology.

The Helping Ourselves, Helping Others: Young Women’s Breast Cancer Study, which opened to accrual in October 2006, is examining biological, medical, and quality-of-life issues in women 40 years or younger. This study sought to determine use of BRCA testing following a breast cancer diagnosis and how that testing might be used to make treatment decisions.

Of 897 women, 780 (87.0%) reported BRCA testing by 1 year after diagnosis, with the frequency increasing significantly from 76.9% in 2006 to 95.3% in 2013 (P < .001).

She said the main factors that contributed to the increasing rates of genetic testing included increased awareness, partly due to the “Angelina Jolie” effect, as well as increased access to testing.

“About 30% of those who were tested told us that their knowledge or concern about their genetic risk had influenced their treatment decision in some way,” Dr Partridge said in an interview on the JAMA Oncology website. Among these women, 86.4% of those who tested positive for a BRCA1 or BRCA2 gene mutation and 51.2% of those who were BRCA negative “chose to undergo bilateral mastectomy” instead of having only the affected breast treated.

Among women who opt for bilateral mastectomy, more than 90% undergo immediate breast reconstruction. This surgery is not without risk: one study found that among 112 women who had risk-reducing mastectomy followed by immediate breast reconstruction, bleeding occurred in 10%, infection in 9%, capsular contracture in 14%, and 33% required reoperation.²