Table 3.

Molecular classification of breast cancer.

LA	ER+ and PR ≥ 20% HER2− Ki-67 < 20%
LB	LB HER2−	LB HER2+
	HER2− ER+ and any of the following: Ki-67 ≥ 20% and/or PR− or <20%	HER2+ ER+ Any Ki-67 and PR
HER2+	ER and PR- HER2+
Basal-like (TNBC)	ER and PR− HER2−
Special Types	ER+ (cribriform, tubular, mucous) ER− (apocrine, medullary, adenoid cystic carcinoma, metaplastic)

ER = estrogen receptor, PR = progesterone receptor, HER2 = human epidermal growth factor receptor, LA = luminal A; LB HER2− = luminal B without HER2 overexpression; LB HER2+ = luminal B with HER2 overexpression; HER2+ = human epidermal growth factor receptor 2 positive; TNBC = triple negative breast cancer.