P-148 Perfect concordance between blood-based and normal tissue-based dihydropyrimidine dehydrogenase polymorphisms suggests that pharmacogenetic screening could be contextual to tumour molecular profiling

5–fluorouracil (5-FU) represents the chemotherapy backbone of almost all GI cancers. Important 5-FU-related toxicities have been traced back to impaired or reduced enzymatic catabolism secondary to dihydropyrimidine dehydrogenase (DPYD) allelic polymorphisms. International guidelines recommend pharmacogenetic DPYD test prior to treatment with fluorouracil, capecitabine, tegafur and flucytosine, and this usually requires an additional blood draw....