Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Medline ® Abstract for Reference 107

of 'Fluoropyrimidine-associated cardiotoxicity: Incidence, clinical manifestations, mechanisms, and management'

A DPYD variant (Y186C) specific to individuals of African descent in a patient with life-threatening 5-FU toxic effects: potential for an individualized medicine approach.
Saif MW, Lee AM, Offer SM, McConnell K, Relias V, Diasio RB
Mayo Clin Proc. 2014;89(1):131.
5-Fluorouracil (5-FU) is commonly administered as a therapeutic agent for the treatment of various aggressive cancers. Severe toxic reactions to 5-FU have been associated with decreased levels of dihydropyrimidine dehydrogenase (DPD) enzyme activity. Manifestations of 5-FU toxicity typically include cytopenia, diarrhea, stomatitis, mucositis, neurotoxicity, and, in extreme cases, death. A variety of genetic variations in DPYD, the gene encoding DPD, are known to result in decreased DPD enzyme activity and to contribute to 5-FU toxic effects. Recently, it was reported that healthy African American individuals carrying the Y186C DPYD variant (rs115232898) had significantly reduced DPD enzyme activity compared with noncarriers of Y186C. Herein, we describe for the first time, to our knowledge, an African American patient with cancer with the Y186C variant who had severe toxic effects after administration of the standard dose of 5-FU chemotherapy. The patient lacked any additional toxic effect-associated variations in the DPYD gene or the thymidylate synthase (TYMS) promoter. This case suggests that Y186C may have contributed to 5-FU toxicity in this patient and supports the use of Y186C as a predictive marker for 5-FU toxic effects in individuals of African ancestry.
Division of Hematology/Oncology and Experimental Therapeutics, Tufts Medical Center, Boston, MA. Electronic address: wsaif@tuftsmedicalcenter.org.