Prediction of clinical response to 5-fluorouracil-containing chemotherapy: preliminary results of in vitro assay in human breast cancer.

Abstract

An in vitro assay system measuring the production of phosphorylated nucleotide products of 5-FU by human tumor cytosols is described. Samples from 11 patients with breast cancer treated with 5-FU-containing chemotherapy regimens were assayed. Significant differences were seen in quantitative and qualitative patterns of phosphorylation between samples from chemotherapy responding and nonresponding patients. The rate of 5-fluorodeoxyuridylate production and the amount of nucleotide triphosphate produced were significantly P < 0.05 increased in chemotherapy-responding patients. This in vitro assay system is a simple, reproducible procedure that requires further evaluation as a potential system for prospectively predicting clinical response to fluorinated pyrimidines.