Impact of sarcopenia status of muscle-invasive bladder cancer patients on kidney function after neoadjuvant chemotherapy.

BACKGROUND Sarcopenia is suspected to influence the complication rates in patients undergoing radical cystectomy (RC). The aim of our study was to assess variations in sarcopenia in patients scheduled for neoadjuvant cisplatin-based chemotherapy (NAC) and RC for muscle invasive bladder cancer (MIBC) and to explore the impact of sarcopenia on complications linked to NAC or surgery. METHODS Between 2012 and 2017, 82 consecutive patients who underwent NAC and RC for cT2-T4 N0 MIBC were retrospectively selected. Using CT scan before and after NAC, Lumbar Skeletal Muscle Index (SMI) was assessed by two observers. We defined severe sarcopenia as SMI <50 cm2/m2 for men and SMI <35 cm2/m2 for women. We evaluated pre- and post-NAC cisplatin-based chemotherapy renal function and post-operative complication rates after cystectomy using the Clavien-Dindo classification. We explored risk factors of complications by logistic regression models. RESULTS According to the SMI, 47 patients (57.3%) were classified as sarcopenic and 35 patients (42.7%) non-sarcopenic. Patients' characteristics between sarcopenic and non-sarcopenic patients were not significantly different except for BMI (P<0.001). Among patients non-sarcopenic before NAC, nine (25.7%) became sarcopenic after NAC. In multivariate analysis, sarcopenia was an independent significant predictor of renal impairment after NAC (P=0.02). Moreover, sarcopenia and ASA score were independent significant predictors of postoperative early complications (P=0.01 and P=0.03, respectively). CONCLUSIONS We observed significant changes in sarcopenic status during NAC. Sarcopenia, estimated by the lumbar SMI measurement, was an independent predictor associated with the risk of renal impairment during NAC and early postoperative complications after RC.