<i>PIK3CA</i>-mutated breast cancer: from research to clinical practice

Mutation or amplification in the PIK3CA gene is one of most frequent somatic mutations hormone-dependent Her2neu-negative breast cancer (HR+ Her2neu- cancer) and associated with an increased risk relapse, progression death. Understanding mechanisms leading to hyperactivation PI3K-mediated signaling cascade has led a new class drugs aimed at inhibiting/suppressing it. Studies efficacy pan-PI3K inhibitor buparlisib beta isoform taselisib were formally positive reached their planned primary sites, but discontinued due high levels toxicity. To date, only phosphatidylinositol 3-kinase (PI3K) approved clinical practice alpelsib, which selectively inhibits alpha enzyme's catalytic subunit. The safety alpelisib combination fulvestrant for treatment postmenopausal women men HR+ HER2- -mutated advanced metastatic after prior therapy aromatase inhibitors was demonstrated SOLAR-1 study. next step proving patients previously treated endocrine CDK4/6 open, multicenter, noncomparative three-arm study BYLieve. current accumulated experience confirms complements findings. In this article, we review cases use who received hormone therapy, including inhibitors.