Clinical impact of postoperative loss in psoas major muscle and nutrition index after radical cystectomy for patients with urothelial carcinoma of the bladder

Background: Although the significance of preoperative nutritional status has been investigated, there is no report regarding the relationship of their postoperative changes on outcomes in patients who underwent radical cystectomy for bladder cancer. Here, we report the clinical impact of the change, from baseline, in nutritional status and volume of abdominal skeletal muscle mass and adipose tissue after radical cystetomy. Methods: A retrospective analysis of 89 patients with bladder cancer, who underwent curative radical cystectomy, was conducted to assess the time course of change, from baseline, in body composition and nutritional status at 1, 3, 6, 12, and 24 months, after surgery. Skeletal muscle mass and abdominal adipose tissue mass were quantified by unenhanced computed tomography images. Two different nutritional indices, the Prognostic Nutritional Index and the Controlling Nutritional Status score were calculated from laboratory blood tests. We evaluated the prognostic value of the rate of change in the body composition and nutritional status after radical cystectomy. Results: The cross-sectional area at the level of the third lumbar vertebra of the psoas major muscle and nutritional indices showed a transient deterioration at 1 and 3 months after radical cystectomy, with a return to baseline values from 6 to 24 months. A <=-10% loss in the area of the psoas muscle was associated with a shorter overall survival, compared to those with a >-10 change [ hazard ratio (HR) 2.2, P = 0.02]. Multivariate analyzes identified sarcopenia status at baseline (HR 2.2, P = 0.03) and a <=-10% loss in the psoas muscle (HR 2.4, P = 0.02) were identified as independent prognostic factors for overall survival. A subanalysis of patients without sarcopenia identified a worse survival outcome for patients with a =-10% loss in the psoas muscle (HR 2.6, P = 0.03) and =-5 change in the Prognostic Nutritional Index (HR 3.6, P = 0.01). Conclusion: Further research is required to establish appropriate rehabilitation protocols and nutritional interventions after radical cystectomy for maintaining skeletal muscle mass and nutrition status which could counteract physical deterioration and improve outcomes.