PIK3CA mutations in breast cancer: Reconciling findings from preclinical and clinical data

Abstract

PIK3CA mutations represent one of the most common genetic aberrations in breast cancer. They have been reported to be present in over one-third of cases, with enrichment in the luminal and in human epidermal growth factor receptor 2-positive subtypes. Substantial preclinical data on the oncogenic properties of these mutations have been reported. However, whilst the preclinical data have clearly shown an association with robust activation of the pathway and resistance to common therapies used in breast cancer, the clinical data reported up to now do not support that the PIK3CA mutated genotype is associated with high levels of pathway activation or with a poor prognosis. We speculate that thi..