Endogenous DNA damage levels in peripheral blood mononuclear cells in patients with muscle-infiltrating urothelial bladder carcinoma.

Abstract

e16020 Background: Cisplatin-based combination chemotherapy is used as a standard neoadjuvant treatment of patients with muscle-infiltrating urothelial bladder carcinoma (MIUBC). DNA damage represents one of the most important factors contributing to its toxicity. The objective of this prospective study is to evaluate the prognostic value of the endogenous DNA damage level in peripheral blood mononuclear cells (PBMCs) from MIUBC patients before treatment with neoadjuvant chemotherapy. Methods: PBMCs isolated from 25 consecutive MIUBC patients (16 men, 64%) were included into this study. Karnofsky index < 80% was present in 1 patient (4%). DNA damage levels in PBMCs were evaluated by the Comet assay and scored as percentage of DNA in tail by the Metafer-MetaCyte analyzing software. Cut-off of 5.25 was used to dichotomize DNA damage level as “high” or “low” based on the previous study. Results: At the median follow-up 12.1 months, 13 patients progressed (52%) and 8 patients (32%) died. The median and IQR (interquartile range) of endogenous DNA damage level was 7.52 (4.07-27.9). Patients with low DNA damage levels had non-significantly better progression free survival (HR = 0.33, 95% CI: 0.09-1.29) and overall survival (HR = 0.64, 95% CI: 0.11-3.87) compared to patients with high DNA damage levels. Conclusions: These data suggest that endogenous DNA damage levels in PBMCs from MIUBC patients may serve as a prognostic marker early identifying patients with poor outcome. This study is supported by VEGA 2/0053/19 and APVV-17-0384.