Comparison of breast cancer surrogate subtyping using a closed-system RT-qPCR breast cancer assay and immunohistochemistry on 100 core needle biopsies with matching surgical specimens

Table 3 Concordance between STRAT4 and IHC for two or more biomarkers

Comparisons	Biomarkers	OPA% (95% CI)
STRAT4 vs IHC, both CNB	4-ways^a STRAT4 vs 4-ways^a IHC (ER, PR, Ki-67 and HER2)	57 (46.7–66.9)
	3-ways^a STRAT4 vs 3-ways^a IHC (ER, Ki-67 and HER2)	64 (53.8–73.4)
	2-ways^a STRAT4 vs 2-ways^a IHC (ER and HER2)	84 (75.3–90.6)
	2-ways^a STRAT4 vs 2-ways^a IHC (ER and Ki-67)	74 (64.3–82.3)
STRAT4 vs IHC, both surgical specimen	4-ways^a STRAT4 vs 4-ways^a IHC (ER, PR, Ki-67 and HER2)	66 (55.8–75.2)
	3-ways^a STRAT4 vs 3-ways^a IHC (ER, Ki-67 and HER2)	70 (60.0–78.8)
	2-ways^a STRAT4 vs 2-ways^a IHC (ER and HER2)	87 (78.8–93.0)
	2-ways^a STRAT4 vs 2-ways^a IHC (ER and Ki-67)	75 (65.3–83.1)

^aAgreement with respect to 4-ways analysis means total concordance with respect to all four biomarkers (ER, PR, Ki-67, and HER2), 3-ways that all three biomarkers match, etc.

ISSN: 1471-2407