[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
Invited Commentary
May 2016

Biomarkers of Fluorouracil Toxicity: Insight From the PETACC-8 Trial

Author Affiliations
  • 1Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
  • 2Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota
  • 3Department of Oncology, Mayo Clinic, Rochester, Minnesota
  • 4Mayo Clinic Cancer Center, Rochester, Minnesota

Copyright 2016 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.

JAMA Oncol. 2016;2(5):662-663. doi:10.1001/jamaoncol.2015.5463

Compared with fluorouracil monotherapy, modern multidrug combination therapies based on fluorouracil (eg, fluorouracil, leucovorin, and oxaliplatin [FOLFOX]) have been shown to dramatically improve outcomes for stage III and IV colorectal cancer in the adjuvant setting. As a consequence of being more effective, combination therapies also tend to be more toxic because the concomitant drugs potentiate the toxic effects of fluorouracil. The types of toxic effects observed, as well as the severity, have been shown to vary greatly between treatment regimens, which may not only differ in the combination of drugs prescribed, but also vary in dose, route of administration, and length of therapy. Deleterious germline variations in the dihydropyrimidine dehydrogenase (DPD) gene (DPYD) have been established as predictors of adverse effects to fluorouracil-based treatments. Three rare DPYD variants have been repeatedly associated with decreased DPD enzyme function and correlated with severe adverse fluorouracil-related toxic effects, DPYD*2A, p.I560S, and p.D949V1; however, a recent meta-analysis2 has cast doubt on whether risk variants for fluorouracil-related adverse effects are generalizable across all fluorouracil-based regimens.