Prognostic Utility of the Cachexia Index in Resectable and Borderline Resectable Pancreatic Cancer Treated with Neoadjuvant Chemotherapy

Objectives: The cachexia index (CXI), integrating skeletal muscle mass, serum albumin, and the neutrophil-to-lymphocyte ratio, has been proposed as a marker of cancer-related cachexia. The objective of this study was to assess the prognostic significance of pre-treatment CXI in patients with resectable or borderline resectable pancreatic ductal adenocarcinoma (PDAC) undergoing neoadjuvant chemotherapy (NAC) followed by resection. Methods: We retrospectively analyzed 75 patients with resectable or borderline resectable PDAC who underwent NAC followed by curative resection (2012–2023). CXI was calculated using total skeletal muscle area (S-CXI) and psoas muscle area (P-CXI). Patients were stratified into low and normal groups using sex-specific tertiles. Results: Baseline and pathological characteristics were comparable between groups. Low S-CXI was significantly associated with shorter recurrence-free survival ( P =0.02) and overall survival ( P =0.013). Multivariate analysis demonstrated that low S-CXI remained independently associated with both recurrence (HR 1.81, P =0.045) and mortality (HR 2.16, P =0.033); lymph-node metastasis was also associated with mortality. P-CXI was not associated with outcomes. Conclusions: Pre-treatment S-CXI showed potential prognostic value for survival in patients with PDAC undergoing NAC followed by resection. This simple index may help identify high-risk patients who could benefit from perioperative multidisciplinary interventions. Prospective validation is warranted.