Come a long way, still a ways to go: from predicting and preventing fluoropyrimidine toxicity to increased efficacy?

[...]450 exonic variants in DPYD with potentially damaging effect have been reported (7). [...]to 5-FU, capecitabine and its downstream metabolites are observed only at low concentrations in plasma due to its intracellular activation, making TDM more challenging (15). [...]pharmacogenetic testing may be even more relevant in Cp-treated patients, where routine TDM currently is not feasible. [...]more research is needed to replicate these associations and better understand the impact of these genes and variants on Cp-related toxicities. Besides genotyping, there have been reports on various phenotypic approaches to detect reduced DPD activity pretherapy. [...]no matter which pretherapeutic tests will eventually find their way into routine care, TDM should always complement these methods, at least for the initial cycles, for optimal FP dose individualization.