Table 2.

Capecitabine and metabolite medians (range) of average concentrations

Compound	BCBM, µM	Serum 4, µM	Serum Cmax, µM	Serum AUC	BCBM/Serum 4
Capecitabine	0.81 (0.12–1.97)	3.17 (0.63–5.57)	9.16 (0.63–47.38)	12.40 (1.05–75.34)	0.28 (0.031–0.81)
5′-DFCR	1.52 (0.19–3.86)	4.78 (0.57–9.67)	18.98 (0.57–33.68)	24.73 (0.74–77.0)	0.36 (0.11–0.67)
5′-DFUR	0.27 (0.03–3.19)	5.15 (0.49–15.96)	26.09 (0.49–69.94)	42.03 (0.67–170.9)	0.06 (0.010–0.58)
5-FU	1.81 (0.10–4.57)	0.38 (0.02–0.79)	1.53 (0.53–8.06)	2.25 (0.67–17.8)	5.64 (1.67–12.9)

For each patient, serum 4 is taken at the time the breast cancer BM is identified. Serum AUCs are calculated until the time of BCBM identification.