Cevik, M.Namal, E.Şener, N.D.Köksal, U.I.Çaǧatay, P.Deliorman, G.Çiftçi, C.2026-01-302026-01-3020221741-05411741-0541https://doi.org/10.2217/pme-2021-0047https://acikerisim2.beykoz.edu.tr/handle/123456789/248Aim: To investigate the association of DPYD, MTHFR and TYMS polymorphisms on 5-fluorouracil (5-FU) related toxicities and patient survival. Materials & methods: A total of 103 colorectal cancer patients prescribed 5-FU were included in the study. Genotyping was conducted for several DPYD, MTHFR and TYMS polymorphisms using a microarray analyzer. Results: DPYD 496A>G polymorphism was found to be significantly associated with 5-FU related grade 0-2, but not severe toxicities (p = 0.02). Furthermore, patients with DPYD 85TC and CC genotypes had longer progression and overall survival times compared to TT genotypes in our study group (log rank = 6.60; p = 0.01 and log rank = 4.40; p = 0.04, respectively). Conclusion: According to our results, DPYD 496AG and GG genotypes might be protective against severe adverse events compared to the AA genotype. Another DPYD polymorphism, 85T>C, may be useful in colorectal cancer prognosis. Further studies for both polymorphisms should be conducted in larger populations to achieve accurate results. © 2022 Future Medicine Ltd.eninfo:eu-repo/semantics/closedAccessAdverse EffectsColorectal CancerDPYDFluoropyrimidinesMTHFRPharmacogeneticsPolymorphismsTYMSArticle10.2217/pme-2021-00472-s2.0-85138447228