Preferential activation of capecitabine in tumor following oral administration to colorectal cancer patients

Capecitabine is a novel fluoropyrimidine carbamate rationally designed to generate 5-fluorouracil preferentially in tumors, which is explained to a great extent by the activity of TP in colorectal tumor tissue, (the enzyme responsible for the conversion of 5′-DFUR to 5-FU), which is approximately four times that in adjacent healthy tissue.