Table 2.

Results for CYP2D6 polymorphisms and their effect on pharmacokinetic parameters

Variant alleles	References	Outcome	Comparison			Significance
3–8,11,14A,15,19,20,40,4x	[24]	C ss T+M1–3	EM/EM vs. Various comb			T (NS); M1–3 (p < 0.001) M3 45 % explained by genotype
3,4,5,6	[19]	C ss T+M1–3	wt/wt vs. wt/* or */*			M3 (p = 0.003)
3,4,6,7,8,9,10,41	[26]	C ss T+M1–3 MRDMTAM/END	EM/EM vs. Various comb			M3: 39 % explained by genotype M2: 9 % explained by genotype
3–6,9,10,41,14,15,17	[32]	MRDMTAM/END	CYP2D6 activity score			p < 10−77
3,4,8,10,41	[36]	C ss T+M1–3	EM/EM vs. Various comb			M3 significant
5,10,41	[23]	C ss T+M1–3	wt/wt vs. wt/*5, wt/*10: *10/*10,*5/*10			M1 (p = 0.077) and (p = 0.006) M3 (p < 0.001); M1(*10) (p = 0.011)
			wt/* vs. *5/*10			M3 (p = 0.001)
2–6,10,41	[41]	C ss T+M1–3	EM vs. PM			M1,3 (p < 0.001)
3–6,9,10,17,41	[16]	C ss T+M1–3	EM/EM vs. PM/PM			M3 (p < 0.001)
33 Alleles	[14]	MREND/DMTAM	wt/wt vs. wt/* vs */*			p < 0.001
4,5,10,36,41,21	[21]	C ss T+M1–3	wt/wt vs. wt/* or */*			M2,3 (p < 0.01) both
2–6	[42]	C ss T+M1–3	EM/EM vs. EM/* vs. PM vs. UM			M1 (p = 0.001); M3 (p = 0.001)
5,10,41	[46]	C ss T+M1–3	wt/wt, wt/* vs. */*			M2,3 (p < 0.001)
2,2A,2AxN,4–6,9,10,17,41	[48]	M1–3	CYP2D6 activity score			M3 (p = 0.0009), Z-endoxifen (p < 0.0001)

CYP cytochrome P450, C _ss steady-state concentration, comb combinations, T tamoxifen, M tamoxifen metabolite; M ₁ N-desmethyl-tamoxifen, M ₂ 4-hydroxy-tamoxifen, M ₃ endoxifen, MR metabolic ratio, EM extensive metabolizer, PM poor metabolizer, UM ultrarapid metabolizer, NS not significant, MR _DMTAM/END metabolic ratio of N-desmethyl-tamoxifen concentration over endoxifen concentration, MR _END/DMTAM metabolic ratio of endoxifen concentration over N-desmethyl-tamoxifen concentration, wt/wt two wildtype alleles, wt/* one wildtype allele and one polymorphic allele, */* two polymorphic alleles