Investigation of DPYD, MTHFR and TYMS polymorphisms on 5-fluorouracil related toxicities in colorectal cancer.

5-fluorouracil (5-FU) is a widely used drug for chemotherapy in colorectal cancer. In this study, we investigated the relationship between the severity of 5-FU induced adverse events and several variations in DPYD, MTHFR and TYMS genes, which encode the enzymes involved in 5-FU metabolism in a total of 103 colorectal patients. We also examined the relationship between the polymorphisms and progression-free and overall survival times of the patients in our study group. Among the variations, DPDY 496A>G polymorphism was found to be associated with 5-FU induced adverse events. Also, the DPYD 85T>C polymorphism was detected to be associated with longer progression-free and overall survival times.