DPYD and UGT1A1 Genotype-Based Dosing for Fluoropyrimidines and Irinotecan Chemotherapy: Variant-Specific Impact on Treatment Intensity and Toxicity.

Variant-specific impact of *DPYD* and *UGT1A1* genotype-guided dosing on toxicity and treatment intensity

This retrospective cohort of 178 patients with actionable DPYD and/or UGT1A1 variants analyzes the variant-specific impact of genotype-guided dosing on toxicity and treatment intensity for fluoropyrimidines and irinotecan. Results show a reduction in severe toxicity from 43% to 16% with adjusted dosing.

Synthesis written by Geno'X. For the full original abstract, please refer to the source publication.

The variant-by-variant granularity in this study is valuable: not all actionable DPYD variants have the same toxicity impact or require the same dose reduction. These data refine the practical implementation of CPIC/DPWG recommendations at laboratory and consultation level.

Clinical impact: 3/3 · Evidence strength: 2/3 · Novelty: 1/2 · Sample size: 1/1 · Publication status: 0/1 → Total: 7/10