Table 1.

Breast Cancer Classification.^a

Intrinsic Subtype	Clinico-pathologic definition	Immunohistochemistry Status			Prognosisc
		ER and/or PR	HER2 overexpression	Ki-67
Luminal A	Luminal A	Positive	No	Low	Good
Luminal B	Luminal B (HER2 negative)	Positive	No	High	Intermediate
	Luminal B (HER2 positive)	Positive	Yes	Any	Poor
HER2 overexpressionb	HER2 positive (nonluminal)	Absent	Yes	Not defined	Poor
Basal-like	Triple negative (ductal)	Absent	No	Not defined	Very Poor

^aTable adapted from St Gallen International Expert Consensus Panel (3).

^bListed in original source as "Erb-B2 overexpression".

^cPrognoses adapted from Dai 2015 (5).