The Impact of Computed Tomography-Defined Sarcopenia on Surgical Outcomes in Patients with Sarcomatoid Renal Cell Carcinoma: A Comprehensive Assessment of Abdominal, Psoas, and Paraspinal Musculature.

INTRODUCTION

This study aimed to evaluate the prognostic impact of computed tomography (CT)-defined sarcopenia, assessed via different muscle groups (total abdominal muscle [TAM], psoas muscle [PM], and paraspinal muscle [PS]), on outcomes in patients with sarcomatoid renal cell carcinoma (SRCC) undergoing surgical treatment.

PATIENTS AND

METHODS

A retrospective cohort of 125 pathologically confirmed SRCC patients (2009-2024) was analyzed. Sarcopenia was defined using sex-specific cut-offs for height-adjusted TAM and PM indices, and absolute PS area at the third lumbar vertebra on preoperative CT. The primary endpoint was overall survival (OS). Statistical analyses included Kaplan-Meier curves, Cox regression, LASSO selection, and bootstrap-validated nomogram construction.

RESULTS

Multivariable analysis identified PS-defined sarcopenia as an independent predictor of worse OS (HR = 2.74, 95% CI, 1.001-7.481, P < .05), while TAM- and PM-defined sarcopenia lacked independent prognostic value. Subgroup analysis revealed significant prognostic association of PS-sarcopenia only in male patients. A nomogram incorporating tumor size, N stage, M stage, platelet-neutrophil ratio, platelet-albumin ratio, and PS-sarcopenia demonstrated good predictive accuracy for 1-, 2-, and 3-year OS (AUCs: 0.807, 0.760, 0.781), with a bootstrap-corrected C-index of 0.750.

CONCLUSION

CT-quantified paraspinal muscle mass is an independent prognostic factor for OS in SRCC patients after surgery, particularly in males, and may serve as a valuable biomarker for risk stratification. A nomogram incorporating PS-sarcopenia shows promising predictive performance for individualized prognosis.