Relationship Between GLIM‐Defined Malnutrition and Postoperative Outcomes After Curative Resection in Patients With Gastroenterological Cancer: Update Systematic Review and Meta‐Analysis

ABSTRACT Background In cancer patients, malnutrition worsens postoperative outcomes, with increased complications and poor prognosis. We aimed to update the impact of malnutrition, as defined by the Global Leadership Initiative on Malnutrition (GLIM) criteria, on postoperative outcomes in patients with gastroenterological cancer after curative resection. Methods We identified observational studies published from inception to April 2, 2025. A systematic review and random‐effects meta‐analysis were performed on studies including adult patients (age > 18 years) with gastroenterological cancer who received surgical treatment and had nutritional status assessments based on GLIM criteria. The primary outcomes were overall survival (OS) and overall postoperative complications, which were defined as events with a Clavien–Dindo (CD) grade ≥ II that occurred within 30 days after surgery. Hazard ratios and relative risk ratios for OS and postoperative complications, respectively, with 95% confidence intervals were pooled. The protocol has been published in PROSPERO (CRD42023434267). Results Twenty‐five studies (28 reports comprising 10 942 patients) were included in the qualitative and quantitative syntheses. Compared with the absence of malnutrition, GLIM‐defined malnutrition probably worsens OS (hazard ratio: 1.88, 95% concordance interval: 1.62–2.18, certainty of the evidence: low) and increases postoperative complications (relative risk ratio: 1.57, 95% concordance interval: 1.34–1.84, certainty of the evidence: low). The risk of bias in each study was moderate or high. Conclusions GLIM‐defined malnutrition probably worsens OS and increases the risk of postoperative complications in patients with gastroenterological cancer after surgery.