Fig. 4: Dual dynamics of clinical stage and HER2 expression before and after neoadjuvant therapy.

Each line represents an individual patient (n = 25), illustrating the change in Clinical stage from baseline (cTN) to post-treatment (ypTN). Line color indicates HER2 expression status, while symbols denote assessment timepoints: triangles represent pretreatment HER2, and squares represent posttreatment HER2. Twelve patients achieved pathological complete response (pCR), for whom HER2 evaluation was not feasible due to the absence of residual tumor tissue.