Preoperative serum sodium is associated with cancer-specific survival in patients with upper urinary tract urothelial carcinoma treated by nephroureterectomy.

Objectives: To assess the impact of preoperative serum sodium concentration on the prognosis of patients with upper urinary tract urothelial carcinoma treated by nephroureterectomy.
Methods: The clinical records of 139 patients treated for upper urinary tract urothelial carcinoma by nephroureterectomy were retrospectively reviewed. Recurrence-free and cancer-specific survival curves were calculated using the Kaplan-Meier method, with the difference between curves evaluated using the log-rank test. A multivariate analysis was carried out by Cox's proportional hazard model to identify prognostic factors.
Results: The median (range) follow-up time was 27 (1-139) months. The median (range) preoperative serum sodium was 141 (134-147) mEq/L. Five-year cancer-specific survival estimates for patients above and below the median preoperative serum sodium were 81.7% (95% confidence interval: 68.7-89.7) and 50.6% (95% confidence interval: 30.3-67.8), respectively. In the multivariate analysis, preoperative sodium concentration, pathological T stage, and lymphovascular invasion were independent and significant prognostic factors for cancer-specific survival. A prognostic model of risk classification for cancer-specific survival involving these parameters was developed, and 5-year cancer-specific survival estimates were 29.9% (95% confidence interval: 14.5-47.0) for the poor risk group (hazard ratio 19.95 [95% confidence interval: 8.5-46.6]; P < 0.001), 81.6% (95% confidence interval: 55.2-93.3) for the intermediate risk group (hazard ratio 5.70 [95% confidence interval: 1.27-25.5]; P = 0.022) and 97.9% (95% confidence interval 85.9-99.7) for the favorable risk group.
Conclusion: These findings suggest for the first time that a low preoperative sodium level predicts a poor survival in upper urinary tract urothelial carcinoma patients treated by nephroureterectomy.
(© 2012 The Japanese Urological Association.)