Specifically, poly ADP-ribose polymerase (PARP) inhibitors such as olaparib have been shown to be an effective adjunct therapy as part of the OlympiA trial to improve survival outcomes in BRCA1/2 hereditary breast cancers [115,116], although recent studies on their use in sporadic breast cancers having somatic BRCA mutations have also yielded promising outcomes, albeit rare [117]. This evidence concerns the gene BRCA1 and breast cancer.