Table 2.
Effect of hormonal status on the TAM pharmacokinetics and its metabolites END, 4-HTAM and NDTAM in the investigated TAM-treated breast cancer patients (n = 40). Data are reported as the geometric mean (95% CI)
| Premenopausal (n = 20) | Postmenopausal (n = 20) | ||||||
|---|---|---|---|---|---|---|---|
| AUCτ (ng*h/mL) | Geometric Mean | 95% CI | Geometric Mean | 95% CI | P-value | ||
| TAM | 2806.78 | 2128.19 | 3701.75 | 4829.41 | 4244.20 | 5495.30 | < 0.001 |
| NDTAM | 11,643.86 | 8132.88 | 16,670.55 | 20,253.09 | 17,886.43 | 22,932.88 | < 0.010 |
| 4-HTAM | 61.67 | 44.15 | 86.15 | 112.23 | 98.75 | 127.55 | < 0.001 |
| END | 192.14 | 111.75 | 330.35 | 452.77 | 355.65 | 576.40 | 0.013 |
| Css (ng/mL) | |||||||
| TAM | 116.95 | 88.67 | 154.24 | 201.23 | 176.84 | 228.97 | < 0.001 |
| NDTAM | 485.16 | 338.87 | 694.61 | 843.88 | 745.27 | 955.54 | < 0.010 |
| 4-HTAM | 2.57 | 1.84 | 3.59 | 4.68 | 4.11 | 5.31 | < 0.001 |
| END | 8.01 | 4.66 | 13.76 | 18.87 | 14.82 | 24.02 | 0.013 |
| Metabolic Ratios | |||||||
| TAM/NDTAM | 0.20 | 0.15 | 0.26 | 0.21 | 0.19 | 0.23 | 0.523 |
| TAM/4-HTAM | 46.27 | 36.67 | 58.39 | 38.12 | 31.79 | 45.70 | 0.177 |
| NDTAM/END | 68.98 | 46.26 | 102.86 | 44.35 | 32.78 | 60.01 | 0.230 |
| 4-HTAM/END | 0.30 | 0.20 | 0.44 | 0.24 | 0.19 | 0.31 | 0.275 |
| Apparent clearance (L/h) | |||||||
| TAM | 7.13 | 5.40 | 9.40 | 4.14 | 3.64 | 4.71 | 0.015 |
Tamoxifen (TAM), endoxifen (END), 4-hydroxytamoxifen (4-HTAM) and N-desmethyl tamoxifen (NDTAM)