Pharmacogenetic association between XRCC1 polymorphisms and improved outcomes in bladder cancer patients following intravesical instillation of epirubicin.

BACKGROUND: XRCC1 is a multi-domain protein associated with bladder cancer. We investigated the relationship between the distribution of XRCC1 polymorphisms (rs915927 and rs2854501) and clinical outcomes following intravesical instillation with epirubicin (EPI) or mitomycin C (MMC). METHODS: A TaqMan assay was performed to determine genotypes of 240 individuals diagnosed with bladder cancer. Logistic regression was used to assess the association between polymorphisms and relapse-free survival (RFS) of patients. Quantitative real-time polymerase chain reaction was performed to determine expression of XRCC1 polymorphisms. Survival curves were generated using the Kaplan-Meier method. RESULTS: Risk of bladder cancer recurrence was significantly reduced in patients receiving EPI who had higher incidences of XRCC1 polymorphisms (P=0.009 for rs915927, P=0.001 for rs2854501). In participants administered MMC, results were not statistically significant. CONCLUSIONS: Polymorphisms in XRCC1 SNP variants (rs915927 and rs2854501) were associated with improved clinical outcomes following EPI treatment.