Automated assessment of Ki-67 in breast cancer: the utility of digital image analysis using virtual triple staining and whole slide imaging.

Aims: Precise evaluation of proliferative activity is essential for the stratified treatment of luminal-type breast cancer (BC). Immunohistochemical staining of Ki-67 has been widely used to determine proliferative activity and is recognised to be a useful prognostic marker. However, there remains discussion concerning the methodology.