An inter-observer Ki67 reproducibility study applying two different assessment methods : on behalf of the Danish Scientific Committee of Pathology, Danish breast cancer cooperative group (DBCG)
Introduction: In 2011, the St. Gallen Consensus Conference introduced the use of pathology to define the intrinsic breast cancer subtypes by application of immunohistochemical (IHC) surrogate markers ER, PR, HER2 and Ki67 with a specified Ki67 cutoff (>14%) for luminal B-like definition. Reports concerning impaired reproducibility of Ki67 estimation and threshold inconsistency led to the initiatio