Incorporation of intermediary products of 5-FU anabolism into colorectal cancer.

In 18 patients intermediary anabolic metabolites of 5-FU were measured in normal colonic mucosa and colorectal cancer tissue of intravenous bolus injection or continuous infusion. Higher total concentrations of 5-FU products were found in the cancers when compared with normal colonic tissue. There appeared to be no evidence, however, that some patients had a selectively increased ability to incorporate 5-FU into their tumours. Overall higher concentrations of tumour incorporation of 5-FU were found after bolus injection rather than the infusion method, although this difference is statistically not significant.