132TiP HCB-ONC001 ELPIS TRIAL: Omission of surgery and sentinel lymph node dissection in clinically low-risk HER2-positive breast cancer with high HER2 addiction and a complete response following standard anti-HER2-based neoadjuvant therapy

In patients with operable early HER2+ breast cancer (BC), neoadjuvant systemic treatment (NST) is a standard approach. Recent studies for dual HER2 blockage regimes revealed pathologic complete response (pCR) rates up to 75%. These data cast doubt on the role of locoregional therapy in this population. In ELPIS trial, our multidisciplinary team proposes to omit surgery and sentinel node dissection (but not radiotherapy) in 25 highly selected patients who achieve, following anti-HER2 NST, a complete response by imaging (MRI) and a negative vacuum-assisted breast biopsy (VAC) in the tumor residual bed.