Survival of Patients With Cancer With DPYD Variant Alleles and Dose-Individualized Fluoropyrimidine Therapy-A Matched-Pair Analysis

J Clin Oncol. 2023 Dec 10;41(35):5411-5421. doi: 10.1200/JCO.22.02780. Epub 2023 Aug 28.


Purpose: DPYD-guided fluoropyrimidine dosing improves patient safety in carriers of DPYD variant alleles. However, the impact on treatment outcome in these patients is largely unknown. Therefore, progression-free survival (PFS) and overall survival (OS) were compared between DPYD variant carriers treated with a reduced dose and DPYD wild-type controls receiving a full fluoropyrimidine dose in a retrospective matched-pair survival analysis.

Methods: Data from a prospective multicenter study ( identifier: NCT02324452) in which DPYD variant carriers received a 25% (c.1236G>A and c.2846A>T) or 50% (DPYD*2A and c.1679T>G) reduced dose and data from DPYD variant carriers treated with a similarly reduced dose of fluoropyrimidines identified during routine clinical care were obtained. Each DPYD variant carrier was matched to three DPYD wild-type controls treated with a standard dose. Survival analyses were performed using Kaplan-Meier estimates and Cox regression.

Results: In total, 156 DPYD variant carriers and 775 DPYD wild-type controls were available for analysis. Sixty-one c.1236G>A, 25 DPYD*2A, 13 c.2846A>T, and-when pooled-93 DPYD variant carriers could each be matched to three unique DPYD wild-type controls. For pooled DPYD variant carriers, PFS (hazard ratio [HR], 1.23; 95% CI, 1.00 to 1.51; P = .053) and OS (HR, 0.95; 95% CI, 0.75 to 1.51; P = .698) were not negatively affected by DPYD-guided dose individualization. In the subgroup analyses, a shorter PFS (HR, 1.43; 95% CI, 1.10 to 1.86; P = .007) was found in c.1236G>A variant carriers, whereas no differences were found for DPYD*2A and c.2846A>T carriers.

Conclusion: In this exploratory analysis, DPYD-guided fluoropyrimidine dosing does not negatively affect PFS and OS in pooled DPYD variant carriers. Close monitoring with early dose modifications based on toxicity is recommended, especially for c.1236G>A carriers receiving a reduced starting dose.

Publication types

  • Multicenter Study

MeSH terms

  • Alleles
  • Capecitabine
  • Dihydrouracil Dehydrogenase (NADP) / genetics
  • Fluorouracil*
  • Genotype
  • Humans
  • Matched-Pair Analysis
  • Neoplasms* / drug therapy
  • Neoplasms* / genetics
  • Prospective Studies
  • Retrospective Studies


  • Capecitabine
  • Fluorouracil
  • Dihydrouracil Dehydrogenase (NADP)

Associated data