Low Skeletal Muscle Mass Predicts Relevant Outcomes in Palliative Urological Oncology: A Systematic Review and Meta-Analysis.

Introduction: Low skeletal muscle mass (LSMM) can be assessed by cross-sectional imaging. LSMM is associated with several clinically relevant factors in various disorders with predictive and prognostic implications. Methods: Our aim was to establish the effect of computed tomography (CT)-defined LSMM on mortality in renal cell cancer (RCC) and urothelial carcinoma (UC) undergoing palliative treatment. The MEDLINE library, Cochrane, and SCOPUS databases were screened for the associations between CT-defined LSMM up to May 2022. In total, 11 studies were suitable for the analysis. Results: The included studies comprised 481 patients with RCC and 394 patients with UC. The pooled hazard ratio for the association between LSMM and overall survival was 1.64 (95% CI: 0.90–2.99), p = 0.10 in univariable analysis and 1.55 (95% CI: 0.91–2.63), p = 0.10 in multivariable analysis for RCC. For UC, the pooled hazard ratio was 2.75 (95% CI: 1.77–4.28), p < 0.00001 in univariable, and 2.77 (95% CI: 1.91–4.02), p < 0.00001 in multivariable analysis. For progression-free survival, it was 2.02 (95% CI: 1.24–3.27), p = 0.004 for RCC and 2.43 (95% CI: 1.59–3.74), p < 0.0001 for UC (univariable analysis). Conclusions: CT-defined LSMM predicts OS and PFS in RCC and UC in the palliative setting. The effect was higher in UC. Therefore, LSMM assessment should be included as a relevant prognostic biomarker in clinical routine. [ABSTRACT FROM AUTHOR]