SAN FRANCISCO – Many younger women diagnosed with triple-negative breast cancers do not get tested for BRCA, despite guideline recommendations, investigators report.
Among 173 women with triple-negative tumors -- lacking the HER2, estrogen and progesterone receptors –17% of those who should have been tested for BRCA according to National Comprehensive Cancer Network (NCCN) guidelines, were not tested.
Women less likely to be tested were those 55 years or older, African Americans, those who list Medicaid as their primary form of insurance, and those with stage 3 disease, reported Staci Aubry, a 4th-year medical student at Rush University Medical Center in Chicago, and her associates.
In an interview, Ms. Aubry said that some of the women who were eligible for genetic testing under the guidelines simply declined it.
“Often patients, if they didn’t have a daughter or if they were older and were in the 50 to 60 [year-old] range, even though they’re still included in the NCCN guidelines to be screened, still refused to be tested,” she said.
NCCN guidelines on genetic and familial high-risk assessment for breast and ovarian cancer susceptibility recommend BRCA genetic testing for all women below age 60 years who are diagnosed with triple-negative breast cancer.
“Some histopathologic features have reported to occur more frequently in breast cancers characterized by a BRCA1 or BRCA2 mutation. For example, several studies have shown that BRCA1 breast cancer is more likely to be characterized as ER-/PR-negative and HER2-negative (i.e., “triple negative”), the guidelines note.
To see whether clinicians were adhering to this recommendation, the investigators searched the Commission on Cancer registry tumor database for cases of triple-negative breast cancers diagnosed from 2006 through 2013.
They identified 173 patients, 105 of whom were younger than 60 and thus recommended for screening. Of this group, 87 (83%) were tested for BRCA, and 15 were found to be BRCA positive, but the remaining 18 patients (17%) were not tested.
When the authors looked at demographic and clinical factors that might have accounted for the differences between women who were tested for the gene and those who were not, four factors stood out. Women who did not get tested were more likely to be 55 or older (P = .002), African American (P = .001), Medicaid insured (P = .021) or to have American Joint Commission on Cancer stage 3 disease (P = .014).
“The main message for clinicians is to be aware that these disparities exist, and keep in mind that these four groups – people who are under Medicaid insurance, between 55 and 60 years of age, African American, or who have higher disease stage – should be targeted for screening,” Ms. Aubry said.