Female family members lack understanding of indeterminate negative BRCA1/2 test results shared by probands.

Genetic test results have important implications for close family members. Indeterminate negative results are the most common outcome of BRCA1/2 mutation testing. Little is known about family members' understanding of indeterminate negative BRCA1/2 test results. The purpose of this mixed-methods study was to investigate how daughters and sisters received and understood genetic test results as shared by their mothers or sisters. Participants included 81 women aged 40-74 with mothers or sisters previously diagnosed with breast cancer and who received indeterminate negative BRCA1/2 test results. Participants had never been diagnosed with breast cancer nor received their own genetic testing or counseling. This Institutional Review Board-approved study utilized semi-structured interviews and surveys. Descriptive coding with theme development was used during qualitative analysis. Participants reported low amounts of information shared with them. Most women described test results as negative and incorrectly interpreted the test to mean there was no genetic component to the pattern of cancer in their families. Only seven of 81 women accurately described test results consistent with the meaning of an indeterminate negative. Our findings demonstrate that indeterminate negative genetic test results are not well understood by family members. Lack of understanding may lead to an inability to effectively communicate results to primary care providers and missed opportunities for prevention, screening, and further genetic testing. Future research should evaluate acceptability and feasibility of providing family members letters they can share with their own primary care providers.