MKI67 and breast cancer: This retrospective study included patients with newly diagnosed primaryinvasive breast cancer with known pathologic (pN) and clinical nodal(cN) status who underwent dynamic contrast-enhanced (DCE) breast MRI atthe authors’ institution between July 2013 and July 2016.Clinicopathologic data (age, estrogen receptor and human epidermalgrowth factor 2 status, Ki-67 index, and tumor grade) and cN and pNstatus were collected.