Prävalenz von PIK3CA-Genmutationen beim Mammakarzinom

Introduction: The AKT/mTOR pathway is activated by phosphorylation of the lipid kinase phosphatidylinositol 3-kinase (PI3K) and regulates proliferation, apoptosis, survival and adhesion of tumor cells. In up to 30% of breast cancers, dysregulation of PI3K is reported, resulting from mutations in the PIK3CA gene that encodes the catalytic subunit (p110a). Hotspots of mutations were described in exon 9 (helical domain, E542K, G > A) and exon 20 (kinase domain, H1047R, A > G). Prevalence and the prognostic impact of the PIK3CA mutations as well as the predictive value with regard to endocrine therapy are controvers…