Association between GPX1 and SOD2 genetic polymorphisms and overall survival in patients with metastatic urothelial bladder cancer: a single-center study in Serbia.

PURPOSE: Purpose: Urothelial bladder cancer (UBC) is the most common malignancy of urinary tract in the developed world. In metastatic UBC, systemic chemotherapy still remains the mainstay of initial treatment. Inter-individual differences in treatment outcome partially may be the consequence of genetic variations in enzymes that modulate oxidative stress. Therefore, we aimed to determine the potential prognostic role of single nucleotide polymorphism (SNP) of the two antioxidant enzymes glutathione peroxidase 1 (GPX1) and superoxide dismutase 2 (SOD2) in metastatic UBC patients treated with cisplatin-based chemotherapy. METHODS: Methods: This prospective single-center hospital-based case-control study included 33 patients with metastatic UBC treated with cisplatin-based chemotherapy and 227 healthy controls. GPX1 SNP (rs1050450) was assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and SOD2 SNP (rs4880) was determined by quantitative PCR (q-PCR). Overall survival (OS) was evaluated using Kaplan­Meier survival analysis during 2-year follow up period, with the log-rank test for prognostic significance. RESULTS: Results: No significant difference was observed in the distributions of GPX1 and SOD2 gene variants between patients and controls (p˃0.05). Regarding GPX1 polymorphism, no impact of GPX1 polymorphism on OS could be demonstrated (p˃0.05). Finally, Kaplan-Meier survival analysis showed no association between SOD2 polymorphism and OS (p˃0.05). CONCLUSIONS: Conclusions: No association was found between polymorphism of GPX1 and SOD2 and OS in patients with metastatic urothelial bladder cancer treated with cisplatin-based chemotherapy.