eligibility_summary
Inclusion: ≥40, ECOG 0–2/KPS>60, HER2+ invasive breast cancer, BCS with axillary staging, ≥4 cycles chemo + HER2 therapy. Adjuvant: pT≤2 cm, pN0, neg margins. Neoadjuvant: pre‑tx tumor <3 cm, cN0 by imaging, ypT0N0 (no DCIS). HIV on ART ok. Exclusion: metastasis, any nodal+, mastectomy, unresolved suspicious findings, non‑epithelial or extensive multifocal/multicentric, synchronous invasive/DCIS, positive margins, nodal RT, prior invasive breast Ca or ipsilateral/thoracic RT, pregnancy/lactation, recent investigational drug.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Phase III HERO (NCT05705401) tests adjuvant whole-breast radiotherapy vs omission in low-risk, early HER2-positive breast cancer receiving standard HER2-targeted therapy after lumpectomy. Interventions: (a) Radiotherapy—local ionizing radiation inducing DNA double-strand breaks, tumor cell death, and immunomodulation. (b) Standard HER2 therapy (continued per SOC): trastuzumab (IgG1 monoclonal antibody, binds HER2/ERBB2, blocks signaling, mediates ADCC), often with paclitaxel (taxane cytotoxic, microtubule stabilizer), or ado-trastuzumab emtansine/T-DM1 (antibody–drug conjugate delivering DM1, a microtubule inhibitor). Targets/pathways: HER2-overexpressing tumor cells, ERBB2→PI3K/AKT/MAPK signaling, microtubules in proliferating cells, DNA damage/repair pathways in irradiated tumor and breast tissue.