The influence of serum sodium concentration on prognosis in patients with urothelial carcinoma treated by radical cystectomy

Serum sodium concentration has been found to be associated with poor survival in many solid tumors. This study investigated the effect of basal serum sodium concentration on prognostic in patients with muscle-invasive bladder cancer (MIBC) undergoing radical cystectomy (RC). MIBC patients with histologically proven urothelial carcinoma treated by RC were retrospectively reviewed. According to the optimal cutoff value, we divided the patients into 2 groups: high-serum sodium concentration group (≥140 mmol/L, n = 39) and low-serum sodium concentration group (<140 mmol/L, n = 32). Overall survival (OS) was estimated with the Kaplan–Meier method and the significance was examined by the log-rank test. Multivariable Cox regression for OS was performed for lymphatic metastasis, hypertension, diabetes mellitus, and tumor size. A total of 71 MIBC patients (60 males and 11 females) were included who underwent cystectomy between 2014 and 2018. The patients’ ages at the time of operation ranged from 44 to 86 years (mean, 66.66 years). Patients’ serum sodium concentration <140 mmol/L had shorter median OS (1224 days (HR: 2.454 [95% CI, 1.083–5.561; P = .031]). In multivariate analysis, lower serum sodium concentration was significantly associated with worse OS after adjusted (adjusted HR: 2.422 [95% CI, 1.055–5.561; P = .037]). Serum sodium concentration <140 mmol/L was independently associated with a poorer prognosis in patients with MIBC used who underwent RC.