Response to letter to the editor: Accurate diagnosis of sarcopenia in elderly requires correct measurement of muscle mass

Decrease in skeletal muscle index 1 year after radical cystectomy as a prognostic indicator in patients with urothelial bladder cancer

PURPOSE

The present study aimed to determine whether sarcopenia after radical cystectomy (RC) could predict overall survival (OS) in patients with urothelial bladder cancer (UBC).

MATERIALS AND METHODS

The lumbar skeletal muscle index (SMI) of 80 patients was measured before and 1 year after RC. The prognostic signifi cance of sarcopenia and SMI decrease after RC were evaluated using Kaplan-Meier analysis and a multivariable Cox regression model.

RESULTS

Of 80 patients, 26 (32.5%) experienced sarcopenia before RC, whereas 40 (50.0%) experienced sarcopenia after RC. The median SMI change was -2.2 cm2/m2. Patients with sarcopenia after RC had a higher pathological T stage and tumor grade than patients without sarcopenia. Furthermore, the overall mortality rate was signifi - cantly higher in patients with sarcopenia than in those without sarcopenia 1 year after RC. The median follow-up time was 46.2 months, during which 22 patients died. Kaplan-Meier estimates showed a signifi cant difference in OS rates based on sarcopenia (P=0.012) and SMI decrease (P=0.025). Multivariable Cox regression analysis showed that SMI decrease (≥2.2 cm2/m2) was an independent predictor of OS (hazard ratio: 2.68, confi dence interval: 1.007-7.719, P = 0.048).

CONCLUSIONS

The decrease in SMI after surgery might be a negative prognostic factor for OS in patients who underwent RC to treat UBC.

Lower skeletal muscle index and early complications in patients undergoing radical cystectomy for bladder cancer

BACKGROUND

Radical cystectomy (RC) is the standard treatment for patients with muscle-invasive bladder cancer (BC), and it is also a valid option for selected patients with high-risk non-muscle-invasive BC. The purpose of this study was to evaluate the effect on the lower skeletal muscle index (SMI) of short-term postoperative complications of radical cystectomy (RC) in patients with bladder cancer (BC).

METHODS

A total of 247 patients who received RC for BC and 204 age-matched healthy population-based controls were retrospectively assessed. SMI was measured by preoperative computed tomography scans at the L4 to L5 level. Early complications were graded by Clavien-Dindo classification; severity of grade III or greater was identified as a severe complication. Logistic regression was utilized to determine the relationships between covariables and severe complications.

RESULTS

A total of 125 (50.61%)/19 (7.69%) patients exhibited overall/severe complications during the early postoperative period. SMI was strongly associated with gender (P <0.01), but not age and body mass index (BMI), among patients with BC. Compared with the matched control group, BC patients exhibited lower SMI. The difference was statistically significant in the subgroup of male patients (P = 0.03). In the multivariate analysis, SMI was an independent predictor of developing severe complications. Each 1 cm²/m² increase in SMI was associated with a decrease in the odds of morbidity by 4.8%.

CONCLUSIONS

A lower SMI is frequently observed in bladder cancer patients undergoing RC and is shown to be strongly associated with early complications following surgery.