Abstract
BACKGROUND: The prognostic and predictive value of obesity and sarcopenia remains poorly defined in patients with high-risk soft tissue sarcoma (HR-STS). We sought to correlate clinical outcomes with CT-based body composition parameters in patients with HR-STS undergoing a multimodal preoperative therapy. The impact of radiologic and histopathologic response to preoperative treatment was correlated with individual fat and muscle distribution. METHODS: Patients with locally advanced non-abdominal HR-STS and treatment with preoperative chemotherapy + regional hyperthermia (RHT) +/- radiotherapy (RT) followed by surgery between 2015 and 2022 were retrospectively evaluated. Body composition parameters measured on baseline CT scans were correlated with clinical outcomes including event-free survival (EFS) and overall survival (OS) as well as radiologic and histopathologic treatment response. RESULTS: A total of 85 patients were included. Body composition parameters showed no significant correlation with radiologic or histopathologic treatment response. High total fat indices such as the total fat index (TFI, HR 3.56, p = 0.005) and high total fat to muscle ratio (FMR, HR 3.22, p = 0.020) were strongly associated with poor OS. Parameters for sarcopenia including skeletal muscle index (SMI) were not significantly linked to survival outcomes. CONCLUSION: High fat indices and a high FMR are strong predictors of poor OS in patients with HR-STS. Larger studies are warranted to further clarify the prognostic impact of sarcopenia and the predictive value of body composition parameters on preoperative treatment response.