BRCA testing and outcomes in women with breast cancer

Abstract

Main purpose Germline BRCA mutations ( BRCA m) strongly influence the risk of developing breast cancer. This study aimed to understand the role of BRCA m testing in affected individuals and to assess its impact on the outcome of BRCA m carriers compared to non-carriers ( BRCA wt) with breast cancer. Research question The research question is “Does standard of care testing for BRCA m improve survival outcomes of breast cancer patients?” Methods In a single institution observational cohort study, demographic and clinical characteristics were compared between breast cancer patients with and without BRCA m. Frequency of BRCA testing was assessed. Survival outcomes were assessed by initial treatment setting stratified by BRCA status. Results Of 5712 identified women with breast cancer, 14.6% ( n \u2009=\u2009835) were tested for a BRCA mutation and had a documented result. The total number and proportion of women tested for a BRCA m increased between 2000 and 2014, resulting in an increased number of BRCA m carriers identified. However, the proportion of women who underwent testing and had a BRCA m decreased during the study period from 27.5% in 2000–2004 to 13.3% in 2010–2014. Disease-free survival was similar in the adjuvant and neoadjuvant treatment settings between BRCA m and BRCA wt patients. Progression-free survival on first line treatment and overall survival for patients with metastatic disease was also similar between BRCA m and BRCA wt patients. Conclusions The proportion of women tested and the number of BRCA m identified increased during the study period despite a decreasing proportion of positive results among women tested.