NEW YORK (GenomeWeb) – More young women with breast cancer are undergoing BRCA1 and BRCA2 mutation testing, according to a Dana-Farber Cancer Institute-led team of researchers.
The researchers asked nearly 900 women under the age of 40 diagnosed with breast cancer between mid-2006 and 2013 whether they'd undergone genetic testing. Some 87 percent of those women reported that they had and, for many of them, that their results influenced their treatment approach, such as choosing a bilateral mastectomy, as the researchers reported in JAMA Oncology today.
"Rates of BRCA1 and BRCA2 mutation testing are increasing in young women with breast cancer," Dana-Farber's Ann Partridge and her colleagues wrote in their paper. "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."
As part of the multicenter Helping Ourselves, Helping Others: The Young Women's Breast Cancer Study, Partridge and her colleagues asked 897 women diagnosed with breast cancer at the age of 40 or younger in a survey a year after their diagnosis whether they'd undergone genetic testing and, if they had, what their results were. They also asked women who hadn't undergone testing why they'd declined to do so and whether they were considering testing in the future. They further inquired about the participants' treatment choices.
Some 87 percent of the women surveyed reported that they were tested for BRCA mutations within a year of their diagnosis, while 13 percent had not undergone testing.
Of the 39 women diagnosed with breast cancer in 2006, nearly 77 percent reported undergoing testing within a year of diagnosis. While that rate fell to 70 percent of women diagnosed in 2007, the BRCA mutation testing rate then climbed to 97 percent of women diagnosed in 2012 and 95 percent of women diagnosed in 2013.
This, Partridge and her colleagues noted, is a much higher rate of testing than other studies have reported and could be attributed to the high levels of education and insurance among the women in the study. It may also reflect that most of them received care at large cancer centers that offer such services.
In addition, the high rates of testing in women diagnosed in 2012 and 2013 could be due to the so-called 'Angelina Jolie effect,' Partridge and her colleagues said. In 2013, the actress and director wrote in the New York Times about her decision to undergo BRCA testing and, based on her results, seek a preventive double mastectomy followed later by the surgical removal of her ovaries and fallopian tubes.
Further, the US Supreme Court ruled in Association for Molecular Pathology et al. v. Myriad Genetics that same year that human genes could not be patented, striking a blow to Myriad, then the only provider of BRCA1 and BRCA2 testing in the US. Following this ruling, the researchers noted that there has been an expansion of testing options that may also influence testing patterns.
The vast majority of the women tested did not have a BRCA mutation, the researchers reported. Of those who were tested, 7.6 percent said they had a BRCA1 mutation, 4.5 percent said they had a BRCA2 mutation, and 4.6 percent said they had an indeterminate result or a variant of unknown clinical significance. Eighty-one percent reported a negative test result.
Most of the 117 women who didn't undergo BRCA mutation testing said that their physician or a genetic counselor had spoken with them about the possibility of genetic risk of disease. Of those that didn't undergo testing, about half didn't think they were at risk for such a mutation. Others said it wasn't a priority or that they were worried about the work or insurance ramifications of a positive result.
This, a trio of researchers from the City of Hope said in a related JAMA Oncology editorial, is "disconcerting."
"[T]he National Comprehensive Cancer Network guideline has recommended genetic counseling and BRCA testing for women with breast cancer diagnosed at 40 years or younger since the outset of the YWS study," City of Hope's Jeffrey Weitzel and his colleagues wrote.
About a third of the women said they'd received their results less than a month after their diagnosis, suggesting to Partridge and her colleagues that the results may have influenced their treatment decisions.
Indeed, nearly 30 percent of the women who underwent testing said that their knowledge or concern about genetic risk influenced their treatment. Of those women, those with mutations more often chose to undergo a bilateral mastectomy, and mutation carriers were also more likely to undergo salpingo-oophorectomy than non-carriers.
However, the researchers also noted bilateral mastectomies were common in their cohort, even among non-carriers; about half of the non-carriers who said their treatment decision was swayed by genetic concerns underwent bilateral mastectomies. This, they said, could be due to patients seeking a sense of peace of mind that they won't develop cancer in the other breast.
While this increased rate of genetic testing among young breast cancer patients is heartening, Weitzel and his colleagues added in their editorial that "[t]he 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. "