Hormonal status affects plasma exposure of tamoxifen and its main metabolites in tamoxifen-treated breast cancer patients

Table 3 Frequencies of CYP2D6 and CYP3A gene variants in the investigated TAM-treated breast cancer patients (n = 40)

Gene		Premenopausal (n = 20)	Postmenopausal (n = 20)
CYP2D6
Activity score	Function	Frequencies of gene variants
0	PM	0	0
0.5	IM	0.15	0
1	Slow NM	0.30	0.2
1.5	NM	0.25	0.35
2	NM	0.25	0.35
> 2	UM	0	0
	others	0.05	0.10
CYP3A5
*3	Variant
	AA (3/3)	0.65	0.7
	AG (3/1)	0.35	0.2
	GG (1/1)	0	0.1
CYP3A4
*1b	Variant
	AA (1/1)	0.8	0.7
	AG (1/1b)	0.2	0.3
	GG (1b/1b)	0	0
*22	Variant
	CC (1/1)	0.9	0.95
	CT (1/22)	0.1	0.05
	TT (22/22)	0	0

ISSN: 2050-6511