MKI67 and neoplasm: Competitive analysis of tumor associated variables and receptor heterogeneity using the ≥1% receptor positivity cut-off in LNM compared to t-CNB revealed that a change (loss or gain) of ER was by trend associated with an increased Ki67 index (40% vs. 10% in the no change group; p = 0.11) and occurred significantly more often in younger patients (median 53 vs. 62 years in the no change group; p < 0.01).