RecruitingDevice studyDiagnostic HER2DX-guided Treatment for Patients wIth Early-stage HER2-positive Breast CancerThe primary goal of the DEFINITIVE trial is to demonstrate the effectiveness of the HER2DX diagnostic assay in enhancing the management of patients with early-stage HER2- positive breast cancer. Patients randomized to arm A will receive adjuvant treatment by physician´s choice, blinded to the diagnostic HER2DX test results. Patients randomized to Arm B will receive personalized treatment according to HER2DX results.