Visual assessment of Ki67 using a 5-grade scale (Eye-5) is easy and practical to classify breast cancer subtypes with high reproducibility

Abstract

Visual assessment of Ki67 by a 5-grade scale (Eye-5) is fast, easy, and reliable with acceptably low interobserver and intraobserver variability. Eye-5 can replace LI in many luminal tumours, and is a strong candidate as a standard method of evaluating Ki67.