Implementing BRCA1/2 Genetic Testing in Patients With Breast Cancer
Based on the results of a retrospective chart review of more than 1100 patients with breast cancer, those meeting at least 1 clinical criterion are significantly enriched for BRCA1/2 mutations, whereas those meeting only 1 criterion test positive for BRCA1/2 mutations at a rate similar to unselected patients. These findings were reported by Caiqian Cropper, MS, CGC, of The University of Texas MD Anderson Cancer Center, Houston, and colleagues, in the June 2017 issue of the Journal of the National Comprehensive Caner Network.
To assess the clinical criteria for BRCA1 and BRCA2 genetic testing in patients with breast cancer outlined by the National Comprehensive Cancer Network® (NCCN®), the investigators evaluated the positive predictive values of 14 individual criteria for predicting these mutations in 1123 patients with breast cancer.
They found that 2 of 115 patients recommended for testing based on the criterion of being diagnosed with breast cancer at 45 years of age or younger had pathogenic mutations at a positive predictive value of 1.6%. In addition, 0 of 37 patients who underwent genetic testing based on the criterion of being diagnosed with breast cancer at any age with at least 2 close blood relatives with breast cancer at any age tested positive. Finally, those who met at least one criterion had a positive predictive value of 12%, compared with 3.2% for those who met one criterion alone—significantly below the 10% for predicting BRCA1/2 positivity.