The main clinical goal of NAC is to down-stage the primary tumor for BCS,yet BCS after NAC has been associated with significantly higher ipsilateral breast tumor recurrences.The accuracy of breast tumor excision in BCS can dramatically reduce IBTR.The main reseason of IBTR might be the uncertain shrinkage modes of the breast cancer after NAC.This clinical trial is firstly carried out to make clear the shrinkage modes of the primary tumor after 3 cycles and whole cycles of NAC,respectively,with whole-mount serial section(WMSS) and three-dimensional(3D) pathological reconstruction of the residual tumor.The second objective is to investigate the predictive value of 3D MRI reconstruction for the shrinkage modes of the primary tumor after NAC.