DPYD variant testing in candidates for fluoropyrimidine treatment: A study protocol

The main purpose of this study is to evaluate the potential clinical impact of pharmacogenetic testing on the reduction of the toxicity in patients treated with fluoropyrimidines. This will be achieved by comparing the frequency of adverse events and the incidence of toxicity of two groups of patients that will differ from each other only in that one will receive pharmacogenetic counseling. The hypothesis is that availability of a pharmacogenetic report prior to treatment initiation has a positive effect. One of the main secondary goals is to analyze allele frequencies and the association of polymorphisms rs895819 (miR27A) and rs1801160 (DPYD*6) with toxicity by conducting an observational study to determine their clinical relevance and standardize a dose adjustment recommendation.