Gender-dependent association of -TSER polymorphism with 5-fluorouracil or capecitabine-based chemotherapy toxicity.

gene encodes for TS enzyme involved in 5-fluorouracil (5-FU) and capecitabine (CAP) metabolism. This study assessed the association of -TSER and 3RG>C polymorphisms with 5-FU/CAP adverse event (AE) incidence. -TSER and 3RG>C polymorphisms were analyzed by use of PCR/PCR-RFLP in 313 5-FU/CAP-treated cancer patients. Female -TSER 2R carriers were at increased risk for 5-FU/CAP AEs (odds ratio: 2.195; p = 0.032). 2R/2R genotype was the only factor that increased risk for delayed drug administration or therapy discontinuation (odds ratio: 5.049; p = 0.016). No other associations were found. -TSER 3R/2R polymorphism was associated with incidence of AEs in female cancer patients. This gender-driven association potentially implicates the ER that, in female patients, potentially regulates TS expression.