Sarcopenia and Response to Neoadjuvant Chemotherapy for Muscle-Invasive Bladder Cancer

Introduction: The objective of the study was to determine whether sarcopenia is associated with pathologic and survival outcomes for patients with muscle-invasive bladder cancer (MIBC) treated with neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC). Patients and Methods: We identified MIBC patients treated with cisplatin-based NAC in our cystectomy registry from 2000 to 2016. Pre- and post-NAC computed tomography images were analyzed with BodyCompSlicer, a validated body composition assessment tool. Sarcopenia was defined as a skeletal muscle index (SMI) below sex-specific international consensus values. Associations of clinical features with pathologic downstaging (<ypT2), major (Clavien III-V) complications, and cancer-specific mortality (CSM) were modeled using multivariable logistic and Cox proportional hazard regression models. Results: A total of 183 patients were identified. Median follow-up was 3.0 years (interquartile range, 1.8-5.0), during which time 79 patients died, including 62 of bladder cancer. SMI declined by a median of 8.4% during NAC treatment. In multivariable logistic regression, neither pretreatment sarcopenia nor the amount of muscle mass loss during NAC was associated with downstaging to <ypT2 disease (P >.05). Meanwhile, only post-NAC sarcopenia (hazard ratio, 1.90; 95% confidence interval, 1.02-3.56; P =.04) was independently associated with an increased risk of CSM. Conclusion: Sarcopenia after NAC and before RC appeared to be prognostic. Although skeletal muscle mass declined significantly during NAC, neither the degree of muscle loss nor pretreatment SMI were significantly associated with downstaging after NAC and RC. These data do not support the use of sarcopenia as a risk stratification tool for selection of patients for or monitoring response to NAC.