Young women with breast cancer increasingly undergo genetic testing for BRCA1 and BRCA2 mutations, according to a new study. Testing also appears to influence surgical treatment decision-making in these women.
“Prior studies have documented underuse of BRCA testing among younger women with breast cancer, although the figures have improved with time,” wrote study authors led by Ann H. Partridge, MD, MPH, of Dana-Farber Cancer Institute in Boston. “In addition to consideration of prophylactic mastectomy, breast cancer survivors with a BRCA mutation can be presented with information about other risk-reducing strategies.”
The new study included 897 women age 40 years and younger at breast cancer diagnosis who participated in the Helping Ourselves, Helping Others: Young Women’s Breast Cancer Study. They were diagnosed between October 2006 and December 2014. The results were published in JAMA Oncology.
In total, 780 of the 897 women (87.0%) reported being tested for BRCA mutations within 1 year after diagnosis. The mean age at diagnosis was younger in those who were tested (35.3 vs 36.9 years; P < .001).
Generally, there was an increasing rate of testing over time, though the rate dipped from 77% in those diagnosed in 2006 to 70% in 2007 before rising steadily through 2012 to 97% and 95% in 2013 (P < .001 for trend).
Among the 780 women who underwent a BRCA mutation test, 81.3% reported a negative result; 7.6% had a BRCA1 mutation, 4.5% had a BRCA2 mutation, and 4.5% had an indeterminate result or an unknown variant. Of the women who did not undergo testing, 68.4% said they had discussed or were counseled regarding BRCA mutations.
There was a clear indication that the test results influenced surgical treatment decisions. A total of 248 women who were tested said that the test results or concern about genetic risks influenced their treatment. Among these women, 76 of 88 BRCA-positive women (86.4%) chose to undergo bilateral mastectomies; 51.2% of the BRCA-negative women also did so (P < .001). Further, 53.4% of the BRCA-positive women elected to have their ovaries removed, compared with only 2.5% of BRCA-negative women (P < .001). Differences in systemic treatment decisions were not significant between BRCA-positive and -negative women.
The authors noted that the high frequency of testing in this cohort likely reflects the fact that most women were insured, educated, and treated at major cancer centers.
In an accompanying editorial, authors led by Jeffrey N. Weitzel, MD, of City of Hope Comprehensive Cancer Center in Duarte, California, noted that a high rate of women who did not undergo testing indicated that they or their physician did not think a BRCA mutation was likely. They called this “disconcerting,” given that the National Comprehensive Cancer Network guidelines have recommended genetic counseling and BRCA testing for young women with breast cancer since this study began.
Still, they wrote that the integration of testing into standard-of-care clinical breast cancer treatment is encouraging. “The task remains to ensure that the benefits of genetic cancer risk assessment reach more individuals and families, including those among underrepresented minorities, with economic disparities, and in low- to middle-income countries.”