ERBB2 and neoplasm: In cN0 patients, SLNB was significantly associated with the period of treatment (42.1% (51/121) during P1, 71.9% (141/196) during P2, and 64.2% (304/473) during P3 ; p<0.0001), tumor subtypes (49.2% (89/181) in Luminal-A tumors, 63.6% (49/77) in Luminal-B HER2−, 65.7% (94/143) in Luminal B HER2+, 56.0% (60/107) in HER2+, and 72.3% (204/282) in TN ; p<0.0001), and cT stages (63.3% (95/150) for cT0-1 tumors, 71.7% (362/505) for cT2, and 31.7% (38/120) for cT3 ; p<0.0001).