Testing for BRCA mutations reaches high levels among young women with breast cancer, study finds

The vast majority of young women with breast cancer are being tested for mutations in the cancer-susceptibility genes BRCA1 and BRCA2, a new study led by Dana-Farber Cancer Institute investigators suggests, and many of them are using the results of those tests to guide their treatment.

The study, published in the Journal of the American Medical Association Oncology, provides encouraging evidence that patients are largely following National Comprehensive Cancer Network guidelines that women diagnosed with breast cancer at age 50 or younger undergo genetic testing. At the same time, however, the researchers found that many patients who don’t carry BRCA1 or 2 mutations are choosing to have both breasts removed, even though their risk of cancer in the unaffected breast is no higher than average.

“Inheriting a mutation in BRCA1 or 2 significantly increases a woman’s risk of developing breast or ovarian cancer, as well as certain other cancers,” says the paper’s first author, Shoshana Rosenberg, ScD, MPH, of the Susan F. Smith Center for Women’s Cancers at Dana-Farber. “While BRCA testing is recommended for young women with breast cancer, there has been little research into how widely these recommendations are being followed, and how concerns about genetic risk affect treatment decisions.”

In the paper, Rosenberg and her colleagues analyzed data from nearly 900 women who were diagnosed with breast cancer at age 40 or younger. All were participants in the Young Women’s Breast Cancer Study, a Dana-Farber-led project that is tracking the treatment, tumor biology, and psychosocial concerns of 1,300 young women diagnosed with breast cancer since 2006.

The researchers found a notable increase in testing for BRCA mutations. Among young patients diagnosed in 2006, 77 percent had a BRCA test. By 2013, the figure had risen to 95 percent.

Nearly 30 percent of these patients said that knowing about, or being concerned about, genetic risk influenced their decisions regarding treatment. Among these patients, 86 percent of those who carried BRCA mutations, and 51 percent of those who don’t, chose to have a bilateral mastectomy, the surgical removal of both breasts.

Researchers say the gratifyingly high percentage of young patients who opt for BRCA testing may be a result of increased media attention to the subject, particularly the well-publicized decision by actress Angelina Jolie to have a double mastectomy after learning she carried a BRCA mutation. “Greater public awareness may have made women more likely to bring up the issue of genetic risk with their physicians, possibly resulting in more testing,” Rosenberg says.

Among the women who had not been tested, some may have not done so because they had more immediate concerns, or gave a higher priority to other decisions about their treatment, the study authors write.

As to why patients who didn’t carry BRCA mutations often chose to have a bilateral mastectomy – even though they didn’t have an elevated risk of developing a new cancer in the unaffected breast – it may be to relieve their anxiety about the disease and provide more peace of mind, the authors suggest.

“We know that developing breast cancer can be especially anxiety-provoking in young women,” Rosenberg remarks. “They may have a sense that because they weren’t ‘supposed’ to develop breast cancer at such an early age, they want to feel that they’re doing everything possible to prevent another occurrence.”

The fact that so many non-BRCA carriers had a bilateral mastectomy “might indicate a need for better communication of their relatively low risk of developing cancer in the other breast,” Rosenberg suggests.

The senior author of the study is Ann Partridge, MD, MPH, a senior physician in the Susan F. Smith Center for Women’s Cancers at Dana-Farber. Co-authors are Shari Gelber, MS, MSW, Bryce Larsen, MA, and Judy Garber, MD, MPH, of Dana-Farber; Kathryn Ruddy, MD, MPH, of the Mayo Clinic; Rulla Tamimi, ScD, of Brigham and Women’s Hospital; Lidia Schapira, MD, of Massachusetts General Hospital; Steven Come, MD, of Beth Israel Deaconess Medical Center; Virginia Borges, MD, of the University of Colorado Cancer Center.

Funding for the study was provided by Susan G. Komen for the Cure; the National Institutes of Health (R25 CA057711); and The Pink Agenda.