400 Background: Acquisition of pancreatic cancer (PC) tissue specimens from endoscopic ultrasound-guided fine needle aspirates (EUS-FNA) is crucial to investigational pancreatic cancer trials seeking to utilize molecular profile directed therapy. Methods: In an ongoing prospective clinical trial we have utilized molecular profiling of EUS-FNA specimens from patients with resectable and borderline resectable pancreatic cancers. Cytologic specimens were evaluated for six biomarkers to guide the choice of neoadjuvant therapy: secreted protein acid rich in cysteine (SPARC), thymidylate synthase (TYMS), ribonucleotide reductase M1 (RRM1), human equilibrative nucleoside transporter 1 (ENT1), excision repair cross-complementing 1 (ERCC), and topoisomerase 1 (TOPO). Final immunohistochemical (IHC) interpretation was scored by a single pathologist using both staining intensity and percent immunochemically reactive cells. Results: The trial has enrolled 99 patients to date; 47 (47%) resectable patients and 52 (52%) borderline resectable patients. No patient experienced a EUS-FNA related complication. IHC profiling was reported in a median of 5 business days (IQR:3). Of the 99 patient samples, 73 (74%) had adequate cellularity for IHC profiling and this was not affected by stage of disease (n = 35, resectable; n = 38 borderline resectable; p = 0.82). Analysis of SPARC expression was limited to specimens with adequate stromal cells for analysis (n = 50, 51%). Among the 73 patients with adequate tissue for profiling, expression profiling was interpreted to be favorable for the following therapeutic agents: nab-paclitaxel, (SPARC, n = 35, 48%), 5-fluorouracil (TYMS, n = 68, 93%), gemcitabine (RRM1, n = 34, 47%; ENT1, n = 38, 52%), platinum agents (ERCC, n = 30, 41%), and irinotecan (TOPO, n = 62, 85%). Conclusions: The use of EUS-FNA specimens for molecular diagnostics is feasible and IHC analysis was possible in 74% of patient specimens, with preservation of stromal components in over 50%. Further refinement of molecular techniques may expand the breadth of analysis which may be performed, to include quantitative polymerase chain reaction and genetic sequencing Clinical trial information: NCIT01726582.
Cercariform cells: Another cytologic feature distinguishing solid pseudopapillary neoplasms from pancreatic endocrine neoplasms and acinar cell carcinomas in endoscopic ultrasound-guided fine-needle aspirates
