ERBB2 and breast cancer: In the entire cohort of HER2-positive/TN breast cancer, the highest diagnostic accuracy to predict axillary pCR based on SUVmax was achieved by using a cut-off of 4.89 on the most FDG-avid axillary lymph node, yielding a sensitivity, specificity, PPV, and NPV of 90%, 69%, 53%, and 95%, respectively (Table 4).