Personal dose monitoring of fluorouracil and metabolites of capecitabine(XELODA)in patients with colorectal cancer patients (PersonaX)

Interventions: capecitabine Primary outcome(s): The correlation between the capecitabine dose and the C1 and C2 levels of 5-FU, unchanged capecitabine, 5’-DFCR, 5’-DFUR in the blood. C1=concentration an hour after administration of capecitabine C2=concentration two hours after administration of capecitabine. Study Design: Single arm Non-randomized