ERBB2 and neoplasm: The proportion of sonographically missed axillary metastases was significant lower in large-sized tumours, grade 3 tumours, presence of lymphangiosis, ER/PR negative tumours, HER2-positive tumours and Ki-67 > 14% (Table 3) as well as nodal metastasis size >5 mm, N2- or N3-disease and extracapsular extension (Table 4).