Plasma thiobarbituric acid reactive substances predicts survival in chemotherapy naïve patients with metastatic urothelial carcinoma

Oxidative stress plays a significant role in development and progression of cancer, including urothelial carcinomas. TBARS (Thiobarbituric acid reactive substances) represents a marker of oxidative stress increased in various diseases. In this prospective study, we tested the hypothesis of plasma TBARS concentration and correlation with survival in chemotherapy naïve MUC (metastatic urothelial carcinoma) patients. Most of subjects (N = 65) were treated with gemcitabine and cisplatin (GC) chemotherapy. Performance status ECOG ≥2 had 11 patients, visceral metastases were present in 43. Based upon the mean of plasma TBARS, subjects were dichotomized into low and high groups. Progression-free survival (PFS), overall survival (OS) and their 95% CI were estimated by Kaplan-Meier method and compared by log-rank test. At median follow-up of 9.6 months, 65 patients experienced progression and 64 died. Subjects with low TBARS had significantly better PFS (HR 0.51) and OS (HR 0.44) opposed to high TBARS. Patients with low TBARS had significantly higher rate of neutropenia G4 and less liver involvement. High TBARS correlated with BMI above 30 kg/m(2). Performance status and plasma TBARS were proven to be independent predictors of PFS and OS. In this study, high TBARS in MUC patients were associated with poor survival, likely due to more aggressive disease activity as reflected in increased liver involvement. Therefore, this biomarker could be used in clinical practice for early identification of patients with worse prognosis, better patient stratification, and treatment decision making.