ERBB2 and breast neoplasm: In comparison to the ALND group, the SLNB group exhibited higher incidences of left breast tumors (52.3%), unknown histological grade (58.0%), T1 staging (25.5%), ER-negative expression (39.9%), PR-negative expression (53.7%), HER2 positive expression (40.7%), HR+/HER2+ subtype (27.0%), and a higher proportion of BCS (48.8%), with all differences being statistically significant (all p < 0.05).