The expanding utility of diagnostic laparoscopy in pancreatic ductal adenocarcinoma.

Abstract

658 Background: Pancreatic ductal adenocarcinoma (PDAC) is often accompanied by radiographically occult metastatic disease. Diagnostic laparoscopy (DL) prevents non-therapeutic laparotomies by detecting occult metastases and guiding treatment. The aim of this study was to assess the clinical utility of DL in patients with PDAC stratified by perceived resectability (resectable, borderline resectable (BR), and locally advanced (LA)) and to identify risk factors for a positive DL. Methods: We retrospectively reviewed the electronic medical records of all PDAC patients without confirmed metastases who underwent DL at a tertiary medical center from January 2018 to June 2024. Data on demographics, imaging, tumor markers, DL findings, and outcomes were collected. Results: 435 patients met the study criteria. Before DL, 115 (26.4%) had perceived resectable, 165 (37.9%) had BR, and 155 (35.6%) had LA disease. DL revealed metastases in 20.0%, 23.0%, and 54.8%, and resection rates were 68.7%, 30.1%, and 5.2% in resectable, BR, and LA cases, respectively. In multivariable analysis, patients with resectable disease had smaller tumors, lower CA 19-9 levels, and were older (all p<0.05). Overall, 146 (33.6%) had metastases on DL, 151 (34.5%) had localized disease on DL but did not proceed to resection, and 138 (31.7%) underwent resection. Metastatic disease on DL was associated with larger tumors, indeterminate extra-pancreatic lesions on imaging, higher CA 19-9 levels, and distal pancreas involvement (all p<0.05). Of metastatic DL cases, 35.6% lacked concerning imaging, and 15.5% had a normal CA 19-9. Conclusions: DL found metastatic disease in one-third of patients and altered management across all resectability groups. Despite imaging advancements and normal tumor markers, DL often detects missed metastases. Given its diagnostic yield, prognostic value, and safety profile, DL should be considered more routinely in staging PDAC. Patients stratified by perceived resectability prior to diagnostic laparoscopy (N = 435). Variable Resectable (n=115) Borderline Resectable (n=165) Locally Advanced (n=155) P-value Age at DL, years, Median [IQR] 70.0 [62.0-75.5] 67.0 [59.0-72.0] 64.0 [59.0-69.0] <0.001 1 Gender, female (%) 44.3 47.3 47.7 0.85 2 Tumor Location (%) <0.001 2 Head of Pancreas 64.3 83.0 52.9 Distal Pancreas 35.7 17.0 47.1 Tumor Size, cm, Median [IQR] 2.7 [1.9-3.5] 3.1 [2.5-3.8] 4.0 [3.4-5.3] <0.001 1 CA 19-9 Prior to DL, U/mL, Median [IQR] 86.0 [27.0-248.0] 210.0 [56.6-608.5] 378.0 [86.3-1576.0] <0.001 3 CEA Prior to DL, ng/mL, Median [IQR] 3.0 [1.9-4.2] 3.2 [2.1-5.7] 5.0 [2.2-10.2] <0.001 3 Underwent Resection of Primary Tumor (%) 68.7 30.1 5.2 <0.001 2 Metastatic DL (%) 20.0 23.0 54.8 <0.001 2 N is the number of non-missing values. DL (Diagnostic Laparoscopy); IQR (Interquartile Range); CA 19-9 (Carbohydrate Antigen 19-9); CEA (Carcinoembryonic Antigen). Tests used: 1 One-Way ANOVA; 2 Fisher’s Exact Test; 3 Kruskal-Wallis.