ERBB2 and neoplasm: Grade III tumours (P < 0.0001), larger tumours (≥5 cm, P < 0.0001) and tumours in pN3 (P = 0.002) were more common in the ER+/PgR-/HER2- group, whereas tumours in pN1 (P = 0.003) were more frequently observed in the ER+/PgR+/HER2- group.