ERBB2 and breast cancer: <h4>Introduction</h4>The SOUND and INSEMA trials have demonstrated the non-inferiority of sentinel lymph node (SLN) biopsy (SLNB) omission in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) early-stage breast cancer (BC) with negative axillary ultrasound undergoing breast-conserving therapy (BCT).