ERBB2 and breast cancer: These variables a priori predicted axillary pCR, which was highly correlated with ER-/HER2- (OR 1.89, p = 0.001), ER+/HER2+ (OR 2.26, p = 0.0002) and ER-/HER2+ (OR 3.26, p < 0.0001) breast cancers.