Biological subtypes of breast cancer: Prognostic and therapeutic implications

Table 2 First generation gene expression signatures

Gene signature	MammaPrint	OncotypeDX	MapQuantDX	Breast cancer ındex	PAM 50 assay
Starting material	FF or stabilized RNA, FFPE	FFPE	FFPE, FF	FFPE	FFPE
Analytical platform	Microarray, RT-PCR	qRT-PCR	Microarray, qRT-PCR	qRT-PCR	nCounter
Number of genes	70	21	97/9	7	50
Indications	Stage I/II, 5 cm, ER (+), Node (-)/[1-3 Node (+)]	ER(+), Node (-)	ER (+), G2	ER (+)	All, Node (-) untreated
Application	Clinical outcome	Clinical outcome, benefit from chemotherapy	Molecular grading prediction of response to TMX	Clinical outcome, prediction of response to TMX	Subtype definition, risk of relapse without treatment
FDA approved	Yes	No	No	No	No
ASCO and NCCN recommendation	No	Yes	No	No	No

FF: Fresh frozen; FFPE: Formalin fixed paraffin embedded; G: Grade; TMX: Tamoxifen.