John Murphy, MDLinx | February 11, 2016
As many as 95% of young women (age 40 and younger) diagnosed with breast cancer now undergo BRCA testing within a year of diagnosis, according to a study published online February 11, 2016 in JAMA Oncology. In addition, genetic test results are influencing patients’ treatment decisions, researchers said.
The study indicates that patients are following the National Comprehensive Cancer Network guidelines, which recommend that women age 50 or younger diagnosed with breast cancer should undergo genetic testing for BRCA1 and BRCA2 mutations. Carriers of these mutations are at increased risk for developing early-onset breast cancer, the researchers noted.
“In 2006, the rates of [BRCA] testing were in the 70% range, and they went all the way up to about 95% by 2012 and 2013,” said the study’s corresponding author Ann H. Partridge, MD, MPH, Founder and Director of the Program for Young Women with Breast Cancer and a Senior Physician in Medical Oncology at Dana-Farber Cancer Institute, in Boston, MA.
The study included 897 women age 40 and younger diagnosed with breast cancer at 11 academic and community medical centers. Of this population, a total of 780 women (87%) reported BRCA testing by 1 year after breast cancer diagnosis (average age at diagnosis: 35.3 years). Of these, 7.6% reported a BRCA1 mutation, 4.5% reported a BRCA2 mutation, and 4.6% reported an indeterminate result or variant of unknown clinical significance.
Results also showed that testing for BRCA mutations increased during the years of the study. Among young women diagnosed in 2006, 77% reported having a BRCA test within a year of diagnosis. By 2013, the proportion tested had risen to 95%.
The rise in BRCA testing may be a result of increased media attention, particularly after actress Angelina Jolie’s well-publicized 2013 announcement to have a double mastectomy after learning she carried a BRCA mutation, the researchers noted.
The authors also attributed the high frequency of BRCA testing to the fact that most women in the study population were insured, educated, and treated at cancer centers where comprehensive genetic counseling and testing services were widely available.
Of the women who were tested, nearly 30% reported that concern about the genetic risk of breast cancer had influenced their treatment in some way. “The majority of these women said that it affected whether or not they underwent a unilateral mastectomy or lumpectomy followed by radiation or a bilateral mastectomy,” Dr. Partridge said. Among carriers of a BRCA mutation, 86% opted for a bilateral mastectomy. Carriers of a mutation also were more likely than noncarriers to have undergone ovary removal.
Interestingly, about half (51%) of women who didn’t carry any mutation still opted for a bilateral mastectomy, even though their risk of cancer in the unaffected breast was no higher than average. This finding suggests “that many women might choose to remove both breasts because of worries about developing another breast cancer and for peace of mind despite knowing they do not carry a known BRCA mutation,” the authors wrote.
“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,” the authors added.
Of the 897 women in the study, only 13% did not undergo BRCA testing when surveyed 1 year after diagnosis. Among the untested women, about one-third said that they had not discussed the possibility that they might have a mutation with their physician or genetic counselor. Another 37% of untested women said they were thinking of being tested in the future.
“While the majority of women are being tested … a small minority, but an important minority, report that nobody even talked to them about the possibility of harboring a genetic predisposition for breast cancer and that they should get tested,” Dr. Partridge said.
“Given that knowledge and concern about genetic risk influence surgical decisions and may affect systemic therapy trial eligibility, all young women with breast cancer should be counseled and offered genetic testing, consistent with the National Comprehensive Cancer Network guidelines,” the authors concluded.
Dr. Partridge describes the study findings in this JAMA Network video.