Implementation and feasibility of DPYD-guided fluoropyrimidine use in a gastrointestinal oncology clinic at an academic medical center.

INTRODUCTION

Genetic variation in DPYD can result in reduced fluoropyrimidine (FP) metabolism and increased risk of severe toxicity. This DPYD test implementation pilot aimed to establish a feasible workflow for DPYD ordering sample collection and FP dose modifications at the University of Florida Health Cancer Institute.

PATIENTS AND

METHODS

Following education on the clinical utility of DPYD testing, a consensus was reached with the University of Florida Health gastrointestinal oncology clinic on an implementation workflow. Novel clinical decision support (CDS) tools were developed including pre- and post-test inline warnings in chemotherapy treatment plans, clickable dose modification buttons, and a pharmacist-facing alert upon medication verification. Primary outcomes were feasibility metrics including rates and timing of test ordering and sample collection, genotype turnaround time, and clinician response to CDS tools (e.g., FP dose modifications).

RESULTS

DPYD was ordered for 201 patients between July 2024 and March 2026. Most (180/201) orders were placed prior to chemotherapy in FP-naïve individuals, and 85% (153/180) were also collected pretreatment. The average genotype turnaround time was 5.0 ± 2.7 days. Results were available prior to chemotherapy for 80.3% (114/142) of all patients who received a FP-containing regimen and for 93.2% (110/118) of those with DPYD ordered and collected pretreatment. Nine patients had a deleterious DPYD variant; all who newly initiated a FP-containing regimen received a 50% dose reduction.

DISCUSSION: DPYD test implementation with customized CDS tools to support test ordering and FP prescribing in an academic oncology clinic is feasible, with the majority of results returning prior to chemotherapy. Integrating new and unique processes into already established workflows helps achieve timely test ordering and sample collection.