Serum concentrations of active tamoxifen metabolites predict long-term survival in adjuvantly treated breast cancer patients

Table 2 Concentrations of tamoxifen and nine metabolites in 86 breast cancer patients

Analyte	Mean (median) serum concentration (nM)	Analytical CV %	Interpatient variability CV %
Tamoxifen	322.2 (287.5)	6.61	45.46
NDtam	723.2 (689.0)	9.55	44.75
Z-4OHNDtam	30.11 (28.15)	6.46	59.01
4'OHNDtam	30.08 (28.13)	8.18	38.09
Z-4OHtam	5.67 (5.30)	6.03	42.32
4'OHtam	7.64 (7.20)	7.54	39.34
Tam-N-ox	119.6 (97.52)	11.04	60.12
NNDDtam	92.69 (81.17)	11.14	50.80
cis-β-OHtam	ND	–	–
z-α-OHtam	ND	–	–

Samples were run in duplicate
Thirteen patients with metabolite levels below the limit of detection are not included in the calculations, leaving 86 patients for further analysis
Analytical CV % indicates average CV between two replicate samples for all patients
CV coefficient of variation, ND not detected

ISSN: 1465-542X