The differential effects of sarcopenia and cachexia on overall survival for pancreatic ductal adenocarcinoma patients following pancreatectomy: A retrospective study based on a large population

Objectives: Both cachexia and sarcopenia have been considered adverse predictors for prognosis in patients with pancreatic cancer; although sarcopenia and cachexia share some similarities, they are still defined as distinct nutritional conditions. We aimed to explore the differential impacts of sarcopenia and cachexia on prognosis for pancreatic ductal adenocarcinoma (PDAC) patients following radical excision.

Methods: From January 2015 to May 2022, 614 patients undergoing surgery for PDAC were retrospectively included. Sarcopenia was defined as the L3 total skeletal muscle index below 52.4 cm² /m² (men) and 38.5 cm² /m² (women). Cachexia was classified according to the following criteria: involuntary weight loss >5% over the past 6 months, or weight loss >2% and BMI <20 kg/m² , or weight loss >2% and sarcopenia.

Results: Of the 614 patients included in the analysis, 62% and 48% were diagnosed with sarcopenia and cachexia, respectively. Kaplan-Meier analysis showed that sarcopenia and/or cachexia were significantly associated with worse overall survival (OS) rather than worse recurrence-free survival (RFS). Moreover, Cox regression analysis revealed that cachexia rather than sarcopenia was an adverse factor for OS in all PDAC patients. For poorly differentiated PDAC, both cachexia and sarcopenia were significantly associated with shorter OS. However, for moderately/well-differentiated PADC, cachexia was an independent factor for adverse OS, but not sarcopenia.

Conclusions: Sarcopenia and cachexia have different effects on OS for PDAC patients undergoing radical excision. This difference may provide some important information for preoperative management.