Weight Loss Following Radical Cystectomy for Bladder Cancer: Characterization and Effect on Survival. 
The purpose of this study was to evaluate the prevalence of postoperative weight loss (WL) following radical cystectomy (RC) and its association with mortality.  Nutritional status is recognized as a potential modifiable risk factor for postoperative complications following RC for bladder cancer.  The American Society for Parenteral and Enteral Nutrition and the Academy of Nutrition and Dietetics recognize WL as a diagnostic measure for malnutrition.  Seventy-one patients underwent RC for bladder cancer between July 2008 and July 2013, in whom peri-operative weights were documented regularly.  The primary predictor variable was substantial WL defined as ≥ 10% WL by postoperative month 1.  Survival was estimated using Kaplan-Meier analysis; logistic regression was used for multivariate analyses.  Mean postoperative WL at 2 weeks was 9.5 lbs (-5.2%), 14.3 lbs (-7.8%) at 1 month, 16.9 lbs (-9.0%) at 2 months, 12.6 lbs (-6.9%) at 3 months, and 8.9 lbs (-4.6%) at 4 months.  Forty-two percent of patients met criteria for substantial WL.  At 19 months median follow-up, the overall mortality rate was 31% (22 of 71), which rose to 64% (14 of 22) in patients who experienced substantial WL (P < .05).  Substantial WL trended towards significance on multivariate analysis (P = .07).  There was a significant decrease in 5-year survival in patients with ≥ 10% WL (log rank P < .05).  Patients experience WL following RC, which may be indicative of malnutrition.  Substantial WL may predict for poor overall survival.  Prospective studies are needed to determine whether nutritional optimization can prevent significant WL and improve outcomes.