HER2DX genomic assay in HER2-positive early breast cancer treated with trastuzumab and pertuzumab: A correlative analysis from a real-world cohort

Abstract Background: HER2DX genomic assay is a genomic tool developed for personalizing care in early-stage HER2-positive breast cancer. This real-world analysis examines its associations with pathological complete response (pCR) and invasive disease-free survival (IDFS) following trastuzumab- and pertuzumab-based neoadjuvant therapy. Materials and methods: Retrospective, observational, single-center study of 156 patients with stage I–III HER2-positive breast cancer treated with dual HER2 blockade–based neoadjuvant therapy between February 2015 and May 2022 at University Hospital A Coruña. HER2DX and clinicopathological variables were assessed