Postoperative weight loss followed by radical cystectomy predicts poor prognosis in patients with muscle-invasive bladder cancer

We aimed to investigate the impact of postoperative weight loss following radical cystectomy (RC) on patients' prognoses. RC and urinary diversion were performed in 512 consecutive patients with muscle-invasive bladder cancer at our hospitals between May 1996 and July 2018. Demographic clinical information, pre- and postoperative serum albumin, hemoglobin, and weight were evaluated retrospectively at 1month. We also evaluated the association of weight loss with complications and overall survival (OS) as estimated using the Kaplan-Meier method and compared using the log-rank test. Risk factors for poor OS were determined by Inverse Probability of Treatment Weighted (IPTW)-adjusted Cox regression analysis. In 385 patients who met the study search criteria, median postoperative weight loss from baseline at 1week and 1month was 1.1 (-1.8%) and 3.2 (-5.4%) kg, respectively. Patients with significant weight loss (defined as 7.5% at 1month) had higher-grade complications within 1month and had significantly shorter OS than those with weight loss of <7.5%. Type of urinary diversion, loss of serum albumin, and loss of hemoglobin were not significantly associated with weight loss. IPTW-adjusted Cox regression analysis showed that such significant weight loss was an independent risk factor for poor OS. Weight loss followed by radical cystectomy was significantly associated with poor prognosis in patients with muscle-invasive bladder cancer.