Prognostic Value of Lumbar Muscle Morphometrics for Survival of Patients with Spinal Metastasis: A Systematic Review and Meta-analysis

Spinal metastasis, a prevalent complication of advanced malignancy, poses significant challenges in patient management due to its potential to compromise spinal stability and quality of life. Accurate prognostication is crucial for tailored therapeutic strategies. This meta-analysis aimed to evaluate the prognostic significance of sarcopenia and lumbar muscle morphometrics in patients with spinal metastasis. Electronic databases, including PubMed, Embase, and the CENTRAL, were searched up to August 2024. Studies were included if they reported quantitative data on sarcopenia or lumbar muscle morphometric parameters and survival outcomes in patients with spinal metastasis. A quantitative meta-analysis was performed with hazard ratio (HR) as the effect size. Heterogeneity was assessed using the Cochran Q test and I2 statistic. Publication bias was evaluated through funnel plot symmetry and Egger's and Begg's regression tests. Our search identified 17 retrospective cohort studies comprising 3,023 patients. Various parameters were employed to assess sarcopenia, encompassing cross-sectional area (CSA) of the psoas muscles (left, right, total, or averaged), the ratio of psoas CSA to vertebral CSA, the ratio of psoas CSA to squared body height, and densities of the psoas or paravertebral muscles. Meta-analysis revealed that total/mean psoas area, when grouped by tertiles or medians, held independent prognostic value for survival outcomes. The ratio of psoas area to vertebral area also demonstrated significant prognostic value when grouped by tertiles or medians. Lumbar muscle morphometrics are independent prognostic factors for survival in patients with spinal metastasis. Integrating of these metrics into clinical decision-making could enhance personalized therapeutic strategies and prognostic accuracy.