This study investigated the association between PIK3CA genotype and pathologic complete response (pCR) rates in human epidermal growth factor receptor 2 (HER2)-positive breast cancer treated with either dual or single anti-HER2 treatment in addition to neoadjuvant chemotherapy.
Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is treated with HER2-targeted agents, such as trastuzumab and lapatinib, that suppress signaling by phosphatidylinositol 3-kinase (PI3K)-Akt and MAPK pathways.
Therefore, we conducted a meta-analysis to assess the association between PTEN loss, PIK3CA mutation and the efficacy of trastuzumab-based treatment in HER2-positive breast cancer patients.
Although Herceptin could down-regulate both phosphatidylinositol 3-kinase (PI3K)/AKT signal and mitogen-activated protein/extracellular signal-related kinase (ERK) kinase 1 (MEK1)/ERK signal in HER2-positive breast cancer cells, PI3K-specific inhibitor but not MEK1-specific inhibitor could decrease the survivin levels.