Prognostic value of lipoprotein-associated phospholipase A2 in older patients undergoing colorectal resection

This study evaluates the clinical utility of preoperative serum Lipoprotein-associated phospholipase A2 (Lp-PLA2) as a biomarker to predict long-term survival and postoperative complications in older patients undergoing colorectal resection. This cohort study included 454 older patients (aged > 60 years) who underwent elective colorectal resection. Preoperative serum Lp-PLA2 levels were quantitatively measured via enzyme-linked immunosorbent assay (ELISA). Receiver Operating Characteristic (ROC) curve analysis was utilized to determine an exploratory cut-off value. The primary endpoints were Overall Survival (OS) and Disease-Free Survival (DFS), while the secondary endpoint was the 30-day incidence of postoperative complications. Survival outcomes and independent risk factors were assessed using Kaplan-Meier curves and multivariable Cox proportional hazards regression models. Time-dependent areas under the ROC curve (AUCs) of Lp-PLA2 for OS and DFS in the malignant subgroup ranged from 0.58 to 0.65, indicating modest discrimination. After adjustment, higher Lp-PLA2 was significantly associated with worse OS (hazard ratio [HR] per 50 ng/mL increment 1.238, 95% CI 1.074–1.427, P = 0.003) and DFS (HR 1.259, 95% CI 1.118–1.419, P < 0.001) in patients with malignant disease. Patients with high Lp-PLA2 (≥ 151.5 ng/mL) experienced more postoperative complications than those with low Lp-PLA2 (31.6% vs. 20.5%, P = 0.010), although the adjusted association was weak and did not reach statistical significance for the dichotomized marker (odds ratio [OR] 1.423, 95% CI 0.817–2.467, P = 0.210). Preoperative serum Lp-PLA2 is a candidate, non-invasive prognostic biomarker in older patients undergoing colorectal resection. Elevated levels were associated with worse overall and disease-free survival in patients with malignant disease, and the proposed cut-off remains exploratory and requires external validation.