BOSTON, Feb. 12 (UPI) -- Nearly 9 in 10 women under 40 diagnosed with breast cancer undergo genetic testing for one of two mutations indicating a chance for relapse within a year of diagnosis, according to a recent study, though most participants were white, educated and had health insurance.
Of women with mutations to the BRCA1 or BRCA2 gene, most had a bilateral mastectomy, as did more than half of women without a mutation, researchers at the Dana-Farber Cancer Institute found.
Testing for the mutation became available in 1996 and has slowly been adopted as a nearly standard practice. Preventive mastectomies have increased in prevalence as a result, and researchers say awareness of the genetic risk has grown significantly since Angelina Jolie had a preventive bilateral mastectomy in 2013.
"We know that developing breast cancer can be especially anxiety-provoking in young women," Dr. Shoshana Rosenberg, a researcher at the Dana-Farber Cancer Center, said in a press release. "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."
Researchers involved with the study, published in the JAMA Oncology, analyzed data on 897 women 40 years or younger collected between 2006 and 2014 as part of the Helping Ourselves, Helping Others: Young Women's Breast Cancer Study.
Overall, 87 percent of women were tested for the mutation within one year of diagnosis. Annually, the proportion of women reporting testing within a year of diagnosis has increased, from 70.2 percent in 2007 to 95.3 percent in 2013.
About one-third of women who did not get tested said it was never discussed with their physician. Also raising concern among researchers, 48 percent of women reported they did not get tested because they or their doctor thought it was unlikely they had a mutation.
Among women who had the mutation, 86.4 percent had a bilateral mastectomy, as did 51.2 percent of women who did not have the mutation.
In an editorial published in JAMA Oncology alongside the study, researchers at City of Hope also note participants in the study were overwhelmingly white, well-educated, and virtually all had health insurance.
"It is unlikely that this level of access to, or participation in, genetic cancer risk assessment would be found in the community setting or among the economically underserved or ethnic minorities," they wrote.
Dana-Farber researchers said they would expect different rates of testing in more ethnically and economically diverse populations. Previous research has shown the mutation also shows up at different rates in ethnic groups, with BRCA1 mutations twice as common in whites as in blacks and BRCA2 mutations 25 percent more common in blacks than in whites.
They note, however, that awareness and access appears to have dramatically increased testing in the last two decades.
"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 said.