Table 3.

Surrogate Definitions of Intrinsic Subtypes of Breast Cancer (Derived from Goldhirsch et al., 2013 [20])

Intrinsic Subtype	Clinicopathologic Surrogate Definition
Luminal A	‘Luminal A-like’ ER positive PR positive HER2 negative Ki-67 ‘low’; <14%
Luminal B	‘Luminal B-like (HER2 negative)’ ER positive PR ‘negative or low’ HER2 negative Ki-67 ‘high’; >14% ‘Luminal B-like (HER2 positive)’ ER positive Any PR HER2 overexpressed or amplified Any Ki-67
Erb-B2 overexpression	‘HER2 positive (nonluminal)’ HER2 overexpressed or amplified ER and PR absent
‘Basal like’	‘Triple negative (ductal)’ ER and PR absent HER2 negative