Near miss or standard of care? DPYD screening for cancer patients receiving fluorouracil

Authors

Lauren E. Winquist, Schulich School of Medicine & Dentistry
Michael Sanatani, Schulich School of Medicine & Dentistry
Richard B. Kim, Schulich School of Medicine & Dentistry
Eric Winquist, Schulich School of Medicine & Dentistry

Document Type

Article

Publication Date

2-1-2021

Journal

Current Oncology

Volume

28

Issue

1

First Page

94

Last Page

97

URL with Digital Object Identifier

10.3390/curroncol28010012

Abstract

5-fluorouracil (5-FU) and its pro-drug capecitabine are widely used anticancer agents. Most 5-FU catabolism is dependent on dihydropyrimidine dehydrogenase (DPD) encoded by the DPYD gene, and DPYD variants that reduce DPD function increase 5-FU toxicity. Most DPD deficient patients are heterozygous and can be treated with reduced 5-FU dosing. We describe a patient with a genotype associated with near complete absence of DPD function, and severe and likely fatal toxicity with 5-FU treatment. The patient was treated effectively with alternative systemic therapy. Routine pretreatment DPYD genotyping is recommended by the European Medicines Agency, and guidelines for use of 5-FU in DPD deficient patients are available. However, outside the province of Quebec, routine pretreatment screening for DPD deficiency remains unavailable in Canada. It is likely our patient would have died from 5-FU toxicity under the current standard of care, but instead provides an example of the potential benefit of DPYD screening on patient outcomes.