Impact of sarcopenia and myosteatosis on early and long-term survival after surgical resection of pancreatic ductal adenocarcinoma

BACKGROUND: Sarcopenia and altered body composition are increasingly recognized as prognostic markers in oncology. In pancreatic ductal adenocarcinoma (PDAC), their time-dependent impact on survival remains unclear. METHODS: Patients with PDAC who underwent resection at Heidelberg University Hospital between 2013 and 2018 were included. Preoperative CT scans were assessed at the L3 level using the automated Body and Organ Analysis (BOA) tool. Sarcopenia Index (SI) and Myosteatosis Fat Index (MFI) were calculated. Multivariable Cox regression was performed for overall survival at predefined postoperative time points. RESULTS: A total of 723 patients were included. Some 140 patients (19.4%) underwent neoadjuvant therapy, while 583 (80.6%) received upfront surgical resection. The median OS for the entire cohort was 26.0 months (95% CI, 23.4 - 28.3). Patients with a low SI exhibited markedly reduced overall survival compared to those with a high SI (p < 0.001). In multivariate Cox regression analyses, a lower SI was independently associated with increased mortality at 90 days (HR: 0.44, 95% CI: 0.24-0.81) and at 1 year (HR: 0.71, 95% CI: 0.56-0.90). A similar prognostic pattern was observed for the MFI, which also showed independent associations with early mortality. Beyond the first postoperative year, this effect diminished and nodal status, resection margin and CA19-9 levels became the predominant predictors of overall survival. CONCLUSIONS: Preoperative sarcopenia and myosteatosis are strong predictors of early mortality after PDAC resection, whereas tumor biology determines long-term outcomes. Automated CT-based body composition analysis may support perioperative risk stratification and targeted prehabilitation strategies.