These data suggest that PIK3CA inhibition targets an important resistance pathway to anti-HER2 therapy, providing rationale for further study of PI3K inhibition in refractory HER2-positive MBC to validate these results.
This study was designed to explore the relationship between PI3K pathway activation and the sensitivity to lapatinib in HER2--positive metastatic breast cancer patients pretreated with anthracyclins, taxanes and trastuzumab.
We investigated the clinical impact of the expression of PTEN, p-Akt and PI3K in HER2-positive metastatic breast cancer (MBC) patients treated with trastuzumab-based therapies.