Table 1. Horizontal comparison among five genetic tests.

Multigene test	Mammaprint	Oncotype DX	PAM50	Endopredict	BCI
Technique	DNA microarray	RT-PCR	RT-PCR	RT-PCR	RT-PCR
Samples	Fresh frozen tissues	FFPE	FFPE	FFPE	FFPE
Recurrence score	Genomic risk score	RS (0–100)	ROR (0–100), ROR-S; ROR-T, ROR-P; ROR-PT; intrinsic subtype	EP (0–15); EPclin	BCI (0–10)
Risk stratification	Low (score <0.4), high (score >0.4)	Low (RS <18); intermediate (RS, 18–30); high (RS >30)	Low; intermediate; high (details are given above)	Low (EP <5, EPclin <3.3); high (EP >5, EPclin >3.3)	Low (BCI <5.0825); intermediate; high (BCI >6.5025)
Clinical validity	van ’t Veer (2002) (3); van de Vijver (2002) (4); TRANSBIG (2006) (5); RASTER (2007) (6); Mook (2009) (7)	NSABP B14 (2004) (8); ECOG2197 (2008) (9); TransATAC (2010) (10); SWOG8814 (2010) (11); WSG Plan B (2016) (12); NSABP B28 (2018) (13); RxPONDER (ongoing)	Parker (2009) (14); Dowsett (2013) (15); TransATAC + ABCSG 8 (2015) (16)	ABCSG 6/8 (2011) (17); EICAM/9906 (2014) (18); ABSCG 8 (2015) (19)	Ma (2008) (20); Zhang (2013) (21); Sgroi (2013) (22); NCIC MA.14 (2016) (23)
Clinical utility	MINDACT (2016) (24)	NSABP B20 (2006) (25); SWOG8814 (2010) (11); TAILORx (2018) (26)	DBCG 77B (2018) (27)	ABCSG 34 (2020) (28); UCBG 2-14 (2020) (29)	aTTom (2019) (30); Noordhoek (2020) (31)

PAM50, mRNA expression of 50 genes; BCI, breast cancer index; RT-PCR, reverse transcription and polymerase chain reaction; FFPE, formalin-fixed and paraffin-embedded tissues; RS, recurrence score; ROR, the risk of recurrence; ROR-S, ROR combined with subtypes; ROR-T, ROR combined with subtypes and tumor size; ROR-P, ROR combined with subtypes and proliferation; ROR-PT, ROR combined with subtypes, proliferation and tumor size; EP, the genetic score of Endopredict; EPclin, the combination of EP score and two clinical factors.