Diagnostic Efficacy of Staging Laparoscopy Compared to CT and PET-CT in Gastric Cancer: A Retrospective Cohort Analysis.

Abstract

Background and Objectives: This study aimed to assess the diagnostic accuracy and prognostic significance of staging laparoscopy (SL) compared to computed tomography (CT) and positron emission tomography-computed tomography (PET-CT) in gastric cancer staging. We evaluated the ability of SL to detect occult peritoneal metastases and influence of SL on survival outcomes across cancer stages and treatment approaches. Materials and Methods: In this retrospective cohort study, 95 patients with gastric cancer underwent preoperative assessment using CT, PET-CT, and SL between 2018 and 2024. Diagnostic performance metrics were calculated for SL, CT, and PET/CT across the local, locally advanced, and metastatic stages. Survival outcomes were analyzed using Kaplan-Meier curves, and comparisons were made using log-rank tests. A multivariable Cox proportional hazards model incorporating interaction terms was used to determine the independent prognostic factors affecting survival, focusing on SL findings and cytology results. Results: The cohort comprised 75 males (78.9%) and 20 females (21.1%), with a mean age of 57.4 ± 10.1 years. The tumor location distribution was predominant in the corpus (31.1%) and cardia. Tumor staging revealed that 48.1% were classified as T3 and 28.8% as T4, respectively. Diagnostic accuracy analysis showed that SL outperformed CT and PET-CT in detecting peritoneal metastasis across all stages. Specifically, SL demonstrated a sensitivity and specificity of 85% and 95% for local disease, 92% and 80% for locally advanced disease, and 95% and 99% for metastatic disease, significantly exceeding those of CT and PET-CT. Patients with SL findings had a median overall survival (OS) of 30 months compared with 20 months for those assessed only with CT and PET-CT (p < 0.05). The stage-specific median OS for SL patients was 40 months in the local, 25 months in the locally advanced (p < 0.05), and 15 months in the metastatic disease (p < 0.01) groups, indicating significant survival benefits. Multivariable Cox regression identified SL findings as an independent factor associated with reduced mortality risk (HR: 0.70, 95% CI: 0.50-0.90, p < 0.01), while positive cytology findings predicted poorer survival (HR: 1.80, 95% CI: 1.25-2.60, p < 0.01). Interaction terms revealed that SL yielded greater survival benefits in patients with metastatic disease (hazard ratio [HR]: 0.60, p < 0.01) and those undergoing systemic therapy (HR: 0.75, p = 0.04). Conclusions: SL provides superior diagnostic accuracy and prognostic information for advanced gastric cancer staging compared with CT and PET-CT. By accurately detecting peritoneal metastasis, SL aids in optimizing treatment plans, particularly in advanced stages, thus potentially improving patient outcomes.