From 2006 to 2013, rates of genetic testing for inherited abnormal BRCA1 and BRCA2 genes increased in women age 40 or younger who were diagnosed with breast cancer, according to a study.
The research was published online on Feb. 11, 2016 by JAMA Oncology. Read “BRCA1 and BRCA2 Mutation Testing in Young Women With Breast Cancer.”
Most inherited cases of breast cancer are associated with one of two abnormal genes: BRCA1 (BReast CAncer gene one) or BRCA2 (BReast CAncer gene two).
Women with a BRCA1 or BRCA2 genetic mutation:
- have up to a 72% lifetime risk of developing breast cancer
- have a much higher-than-average lifetime risk of ovarian cancer; estimates range from 17% to 44%
U.S. guidelines say that BRCA testing should be considered when:
- many women in a family have been diagnosed with breast and/or ovarian cancer, particularly if the women were younger than 50 when diagnosed
- some women in a family have been diagnosed with cancer in both breasts
- there is both breast and ovarian cancer in a family
- men in a family have been diagnosed with breast cancer
- there is breast cancer in a family and either male relatives on the same side of the family have been diagnosed with prostate cancer at a young age or relatives on the same side of the family have been diagnosed with gastrointestinal cancers, such as pancreas, gall bladder, or stomach cancer
- a family is of Ashkenazi (Eastern European) Jewish descent
National Comprehensive Cancer Network guidelines recommend that women diagnosed with breast cancer at age 40 or younger have genetic counseling and BRCA genetic testing.
The data for this analysis was collected as part of the Helping Ourselves, Helping Others: Young Women’s Breast Cancer Study, an ongoing study of breast cancer in women who were 40 or younger when diagnosed. The women in the study were mostly white, well-educated (85% had completed college and/or graduate school), and almost all of them had health insurance.
Of the 897 women in the study, 780 (87%) said they had had BRCA genetic testing within 12 months after being diagnosed. The rates of genetic testing by year were:
- of 39 women diagnosed in 2006, 30 (76.9%) were tested
- of 124 women diagnosed in 2007, 87 (70.2%) were tested
- of 127 women diagnosed in 2008, 102 (80%) were tested
- of 97 women diagnosed in 2009, 85 (88%) were tested
- of 122 women diagnosed in 2010, 109 (89%) were tested
- of 113 women diagnosed in 2011, 103 (91%) were tested
- of 146 women diagnosed in 2012, 141 (96.6%) were tested
- of 129 women diagnosed in 2013, 123 (95.3%) were tested
The researchers said the high numbers of women tested was likely because most of the women were insured, educated, and treated at cancer centers where comprehensive genetic counseling and testing services were widely available. The media attention that was focused on inherited breast cancer genes after actress Angelina Jolie revealed her own positive test results and prophylactic mastectomy also may have made more women aware of the subject and more likely to discuss it with their doctors. The researchers suspect that low-income and minority women would probably not have access to the same level of service.
The genetic test results showed:
- 59 women (7.6%) had an abnormal BRCA1 gene
- 35 women (4.5%) had an abnormal BRCA2 gene
- 35 (4.6%) had results that couldn’t be determined or a variant of unknown clinical significance
- 634 (81.3%) had negative test results, meaning no abnormal gene was found
A variant of unknown clinical significance means the genetic testing found an abnormal gene, but doctors aren't sure what, if anything, this abnormal gene does in the body.
Of the 117 women who didn’t have BRCA genetic testing, 68.4% said they had discussed testing or were counseled about the possibility of having an abnormal BRCA gene with their doctor or a genetic counselor. This means that 31.6% of the women didn’t talk about the issue with their doctor or a genetic counselor.
About 18% of the women who didn’t have testing said it was because of possible work or insurance discrimination. About 11% said they didn’t have testing because they couldn’t afford it.
Of the women who did have genetic testing and had either positive or negative results, about 30% said that concern about genetic breast cancer risk influenced their treatment choice. Of these women:
- 86.4% of women with an abnormal BRCA1 or BRCA2 gene had a double mastectomy
- 51.2% of women with no known abnormal gene had a double mastectomy
“Bilateral mastectomy was still relatively common in our study even among noncarriers, suggesting 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 researchers said. “It might also suggest a need for better communication of the relatively low risk of contralateral breast cancer [breast cancer in the opposite breast] among women who are noncarriers, that this risk has been decreasing in recent years, and that bilateral mastectomy is not associated with improved survival.”
In an editorial accompanying the article, researchers from the Division of Clinical Cancer Genetics at the City of Hope Cancer Center write, “We share the concerns of the authors that 51% of women in their study chose bilateral mastectomy despite being BRCA negative. While potentially reflecting the overall trend toward increased uptake of bilateral mastectomy among young women in cancer registries, this is markedly higher than the 9% to 21% rate reported in previous studies...”
If you’ve been diagnosed with breast cancer at age 40 or younger, current guidelines recommend that you should have genetic testing for an inherited abnormal BRCA1 or BRCA2 gene.
You are substantially more likely to have an abnormal breast cancer gene if:
- You have blood relatives (grandmothers, mother, sisters, aunts) on either your mother's or father's side of the family who had breast cancer diagnosed before age 50.
- There is both breast and ovarian cancer in your family, particularly in a single individual.
- There are other gland-related cancers in your family such as pancreatic, colon, and thyroid cancers.
- Women in your family have had cancer in both breasts.
- You are of Ashkenazi Jewish (Eastern European) heritage.
- You are Black and have been diagnosed with breast cancer at age 35 or younger.
- A man in your family has had breast cancer.
Still, it’s important to know that most people who develop breast cancer don’t have an abnormal BRCA gene. The results of this study show that only about 13% of the women who were tested had an inherited abnormal BRCA gene.
When you’re first diagnosed with breast cancer, fears about the future can affect how you make decisions. This is especially true for women who have an abnormal breast cancer gene. You have to make a number of decisions at a very emotional time when it can be hard to absorb and understand all the new information you’re being given.
At Breastancer.org, we support every woman’s right to make treatment decisions based on the characteristics of the cancer she’s been diagnosed with, her medical history, her risk of recurrence or a new breast cancer, and her personal preferences. But it’s very important to make sure you understand all the pros and cons of any treatment or procedure you’re considering, including how the treatment or procedure may affect your reconstruction options and if the treatment is likely to make you live longer.
If you’ve been diagnosed with breast cancer at a young age, ask your doctor about ALL of your treatment and risk reduction options. Contralateral prophylactic mastectomy is only one of these options and is an aggressive step. While it may be the right decision for you, give yourself the time you need to consider the decision carefully. It’s a good idea to talk to your doctor about how the details in your pathology report may affect your future risk. You want to be sure that your decisions are based on your actual risk of recurrence or a new cancer. Make sure you understand the benefits and risks of all your options. Together, you and your doctor can make the choices that are best for you and your unique situation.
For more information on BRCA1 and BRCA2 testing and counseling, visit the Breastcancer.org Genetic Testing pages.
Editor’s Note: This article was updated on Jan. 22, 2019, with updated information on cancer risks associated with BRCA mutations.