The Utility of EUS-FNA to Determine Surgical Candidacy in Patients with Pancreatic Cancer after Neoadjuvant Therapy

Abstract

In patients with borderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) who undergo neoadjuvant therapy, CT imaging is the standard of care for restaging. However, differentiating residual tumor from post-treatment inflammation with CT is unreliable. The diagnosis of periarterial soft tissue cuffing (PSTC) near major vessels is key to guiding resectability. The goal of this study was to assess the utility of EUS-FNA in determining the etiology of PSTC in BRPC or LAPC after neoadjuvant treatment. We performed a retrospective analysis of patients referred for EUS-FNA of PSTC following downstaging therapy for LAPC or BRPC at our tertiary medical center. Negative EUS-FNA cytology results were compared with surgical pathology after resection. Patients with positive EUS-FNA cytology results were either followed clinically or results were compared to surgical pathology if surgery was attempted despite the positive cytology. Fourteen patients were included in the study of whom four had positive cytology. Two of these patients had progression of disease, and two had attempted resection with positive surgical pathology (100% true positives). All ten patients with negative cytology underwent attempted surgical resection. Nine patients (90%) achieved negative margins, and one patient (10%) had a positive surgical margin. The sensitivity, specificity, and accuracy of EUS-FNA for determining resectability were 80%, 100%, and 92.9%, respectively. In this series of patients with BRPC or LAPC and persistent PSTC after downstaging neoadjuvant treatment, EUS-FNA accurately determined surgical resectability and should be considered as part of the evaluation of such patients.