biostudies-literatureUnknown13(11)Dolat MIn order to limit 5-fluorouracil (5-FU) toxicity, some health agencies recommend evaluating dihydropyrimidine dehydrogenase (DPD) deficiency before any 5-FU treatment introduction. In our study, we investigated relationships between 5-FU clearance and markers of DPD activity such as uracilemia (U), dihydrouracilemia (UH2)/U ratio, or genotype of the gene encoding DPD (DPYD). All patients with gastrointestinal cancers who received 5-FU-based regimens form March 2018 to June 2020 were included in our study. They routinely benefited of a pre-therapeutic DPYD genotyping and phenotyping. During 5-FU infusion, blood samples were collected to measure 5-FU steady-state concentration in order to adapt 5-FU doses at the following cycles. A total of 169 patients were included. Median age was 68 (40-8Pharmaceuticals (Basel, Switzerland)E416https://www.ebi.ac.uk/biostudies/studies/S-EPMC7700344biostudies-literatureAssociation of 5-FU Therapeutic Drug Monitoring to DPD Phenotype Assessment May Reduce 5-FU Under-Exposure.PMC7700344Dolat MGoirand FGhiringhelli FVincent JMacaire PBengrine-Lefevre LRoyer BPalmier RHennequin ASchmitt AfalseAssociation of 5-FU Therapeutic Drug Monitoring to DPD Phenotype Assessment May Reduce 5-FU Under-Exposure.In order to limit 5-fluorouracil (5-FU) toxicity, some health agencies recommend evaluating dihydropyrimidine dehydrogenase (DPD) deficiency before any 5-FU treatment introduction. In our study, we investigated relationships between 5-FU clearance and markers of DPD activity such as uracilemia (U), dihydrouracilemia (UH2)/U ratio, or genotype of the gene encoding DPD (DPYD). All patients with gastrointestinal cancers who received 5-FU-based regimens form March 2018 to June 2020 were included in our study. They routinely benefited of a pre-therapeutic DPYD genotyping and phenotyping. During 5-FU infusion, blood samples were collected to measure 5-FU steady-state concentration in order to adapt 5-FU doses at the following cycles. A total of 169 patients were included. Median age was 68 (40-82020-01-01T00:00:00Z2020 Nov2025-04-04T22:36:52.647Z2021-02-20T03:07:30ZS-EPMC77003443323848710.3390/ph13110416