Abstract
BACKGROUND: Gastric cancer (GC) is the fifth most prevalent and fourth most lethal malignancy globally. China bears a disproportionately high burden, accounting for 44.0% of new cases and 48.6% of deaths worldwide. In early GC (EGC), the presence of lymph node metastasis (LNM) is a critical prognostic determinant that directly guides therapeutic strategy. While multi-detector computed tomography (CT) and serum biomarkers carcinoembryonic antigen (CEA)/carbohydrate antigen 19-9 (CA19-9) are established diagnostic tools, each demonstrates limited efficacy when used independently. This study therefore aims to verify whether a combined diagnostic approach integrating multi-detector CT (MDCT) with serum CEA/CA19-9 can significantly improve the accuracy of LNM detection in EGC patients. AIM: To investigate the diagnostic value of CT combined with CEA or CA19-9 for detecting LNM in EGC. METHODS: This retrospective study included 120 patients with EGC confirmed by gastroscopic biopsy at our institution (Huai'an Hospital of Huai'an City) between February 2024 and August 2024. Based on postoperative pathological findings, participants were categorized into a LNM group (n = 60) and a non-metastasis group (n = 60). All patients underwent MDCT scanning and serum CEA and CA19-9 level measurements. The diagnostic efficacy of CT, CEA, and CA19-9 alone and in combination was evaluated using receiver operating characteristic (ROC) curve and Kappa consistency analysis. RESULTS: Serum analysis showed significantly elevated CEA and CA19-9 levels and higher positivity rates in the metastasis group (P < 0.0001). ROC analysis yielded area under the curves of 0.9443 (CEA) and 0.9292 (CA19-9), with Kappa values of 0.683 and 0.650, respectively. CT revealed significantly greater short-axis diameter, CT attenuation, blood volume, and permeability in metastatic nodes (P < 0.05), whereas blood flow and mean transit time showed no significant differences. CT alone demonstrated 85.00% sensitivity and 95.00% specificity (Kappa = 0.800). Combined diagnosis improved sensitivity to 91.67% (CT + CEA) and 90.00% (CT + CA19-9), with specificities of 90.00% and 88.33%, respectively. CONCLUSION: The combination of CT with CEA or CA19-9 improves sensitivity for detecting LNM in EGC, supporting personalized treatment planning and demonstrating clinical value.