ERBB2 and cancer: In BRCA-mutated cancers, PARPi have been shown to be very effective in homologous recombination repair deficient tumors, such as BRCA mutations, due to a synthetically lethal interaction.[14,15]According to the National Authority of Medicines and Health Products, olaparib is approved for monotherapy in BRCA-mutated locally advanced or metastatic breast cancer HER2 negative previously treated with an anthracycline-or taxane-based regimen in the (neo)adjuvant or metastatic setting.