Perioperative Outcomes of Patients With Pancreatic Neuroendocrine Neoplasms in the Context of Different Body Composition Phenotypes

BACKGROUND: Pancreatic neuroendocrine neoplasms (pNEN) are rare and heterogeneous tumors with increasing incidence. While surgical resection remains the only curative treatment, perioperative outcomes are influenced by patient-related risk factors. Recent research highlights body composition (BC) as a prognostic marker in oncological and transplantation surgery that reflects the tumor-host interplay. This study describes the association between preoperative assessment of BC phenotypes and major complications following surgery for pNEN. METHODS: All 623 consecutive patients who underwent surgery for pNEN at the University Hospital Heidelberg between 2010 and 2023 were retrospectively screened for inclusion. BC was assessed using preoperative CT scans at the L3 level with a deep learning-based tool (Mosamatic). Parameters included skeletal muscle index (SMI), muscle radiation attenuation (SM-RA), visceral and subcutaneous fat, and derived definitions of sarcopenia, myosteatosis, sarcopenic obesity, and visceral obesity. Postoperative (major) complications were classified according to Clavien-Dindo (CD ≥ 3) and the Comprehensive Complication Index (CCI). Logistic regression was used to identify predictors of 90-day morbidity. RESULTS: A total of 481 patients with suitable CT-scans were included. Mean age was 58 years and 53.8% were male. Obesity was present in 24.3%, sarcopenia in 60.5%, myosteatosis in 50.3%, sarcopenic obesity in 4%, and visceral obesity in 61.1%. Obesity (postoperative pancreatic fistula B/C 33% vs. 19.9%, p = 0.014), visceral obesity (CCI 23.6 vs. 16.4, p = 0.001) and myosteatosis (stay 12 vs. 10 days, p = 0.037) were associated with significantly higher complication rates, longer hospital stays, or increased CCI. In multivariate analysis, ASA ≥ 3, overweight and prolonged surgery remained independent predictors of major complications. CONCLUSION: This study describes the role of BC in patients undergoing surgery for pNEN showing that impaired BC is highly prevalent in pNEN patients. Obesity-related phenotypes and myosteatosis show a potentially negative impact on perioperative outcomes, underscoring the relevance of BC assessment in preoperative risk stratification and surgical decision-making.