Gene expression profiling of primary HER2-positive breast cancers before and after brief exposure to single agent neoadjuvant trastuzumab

Tumor incisional biopsies were obtained at baseline and after brief-exposure to single-agent trastuzumab from patients enrolled on the TRastuzumab-UPfront-in-HER2-positive-locally-advanced- BC (TRUP) window-of-opportunity trial. Gene expression profiling was conducted on these tumor biopsies to identify transcriptional features at baseline and changes upon brief-exposure to trastuzumab associated with response to short term trastuzumab and the complete pre-operative therapy Gene expression profiling was performed using RNA from frozen core biopsies from 17 patients with primary HER2-positive (HER2+) tumors before and after brief-exposure treatment with single agent neoadjuvant trastuzumab.