An in-depth analysis on the effects of body composition in patients receiving neoadjuvant chemotherapy for urothelial cell carcinoma.

Introduction: Neoadjuvant chemotherapy (NAC) is the standard of care for patients undergoing radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC); however, NAC can be associated with significant side effects and morbidity in some patients. NAC may contribute to sarcopenia, obesity, and the combination of the two. Our study examined the effects of NAC on body composition and the association between body composition and adverse events.

Methods: We created a retrospective database of patients with non-metastatic MIBC receiving NAC prior to RC. The change in skeletal muscle index (SMI) and fat mass index (FMI) was calculated using computed tomography (CT) scans done within three months prior to NAC and after the first two cycles. The association between body composition (sarcopenia, obesity, and sarcopenic obesity) and preoperative adverse events was investigated using a multivariable logistic regression. Changes in body composition were calculated using a paired Student's t-test.

Results: A total of 70 patients were included in our study. There was a mean decrease in SMI of 2.2±3.2 cm²/m². Adiposity and FMI were unchanged by NAC. Sarcopenic obesity was found to be associated with adverse events among patients receiving NAC in the multivariable analysis. There was a total of 637 preoperative complications with grades 1-2 and 33 complications with grades 3-5.

Conclusions: Based on our retrospective cohort study, NAC did not affect obesity and FMI, but there was a significant decrease in SMI. Sarcopenic obesity was associated with increased severity of NAC adverse events. As such, the presence of this factor may help predict tolerance of NAC.