Abstract B071: Physiologic Duodenal Aspiration Liquid Biopsy Enables Early Risk Stratification in Pancreatic Cystic Neoplasms

Abstract Early identification of high-risk pancreatic cystic neoplasms (PCNs) is critical for prevention of pancreatic ductal adenocarcinoma, yet current diagnostic tools remain limited in sensitivity and specificity. We developed a physiologic and minimally invasive method—Duodenal Aspiration Liquid Biopsy (DALB)—to obtain pancreaticobiliary secretions for cytological and biochemical analysis prior to endoscopic ultrasound (EUS) or biopsy. This study aimed to assess the clinical utility of DALB for early risk stratification in patients with PCNs. Between 2023 and 2025, we prospectively enrolled 35 patients with PCNs detected on MRI or CT. Before performing EUS or other invasive procedures, we used the Pandicath system to isolate the duodenal segment surrounding the major papilla and collect a physiologically stimulated secretion sample after oral liquid intake. The aspirate was analyzed for carcinoembryonic antigen (CEA) and cytological abnormalities. Patients were stratified into three risk groups: high risk (CEA >192 ng/mL and/or atypical cells), intermediate risk (CEA 100–192 ng/mL), and low risk (CEA <100 ng/mL). All patients subsequently underwent EUS-guided fine-needle aspiration (EUS-FNA) and were followed for up to 36 months. Four patients (11.4%) were classified as high risk. Three of these had atypical cells identified by both DALB and EUS-FNA and underwent surgical resection. Histopathology confirmed high-grade dysplasia in two cases and moderately differentiated adenocarcinoma in one. The fourth patient, without atypia, remained stable during follow-up. DALB classification diverged from imaging-based assessment in 4 cases (11.4%), directly influencing clinical decision-making. Among four intermediate-risk patients, one progressed to surgical indication during observation by MRI and EUS signs but declined surgery. In the low-risk group (n=27), no malignant transformation occurred. One patient underwent elective resection for mass effect from a 12-cm cyst; histology revealed a mucinous cystic neoplasm without dysplasia (CEA in juice was 42.18 ng/mL). No DALB-related complications were reported. DALB is a safe, scalable, and physiologically relevant technique that enables early, noninvasive risk stratification in patients with PCNs. Its results showed full concordance with EUS-FNA in cytologic detection and provided clinically actionable data in cases where imaging was inconclusive. A prospective multicenter validation study is currently underway. Citation Format: Aleksei Kashintsev, Mikhail Dinikin, Yuri Gulyaev, Anastasya Paratovskaya, Mikhail Agapov, Yuri Pelipas. Physiologic Duodenal Aspiration Liquid Biopsy Enables Early Risk Stratification in Pancreatic Cystic Neoplasms [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research—Emerging Science Driving Transformative Solutions; Boston, MA; 2025 Sep 28-Oct 1; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2025;85(18_Suppl_3):Abstract nr B071.