Mo1477 FISH Analysis of Aspirates Increases the Sensitivity of EUS-Guided FNA for the Diagnosis of Pancreatic Adenocarcinoma

Abstract

EUS to exclude, detect and stage ampullary lesions and perform biopsy or FNA. EUS excluded suspected malignant disease in 43% of cases. Mo1477 FISH Analysis of Aspirates Increases the Sensitivity of EUS-Guided FNA for the Diagnosis of Pancreatic Adenocarcinoma Jose-Guillermo De La Mora-Levy*, Juan O. Campuzano, Judith Cruz-Velazquez, Octavio Alonso, Julio Sanchez Del Monte, Sergio R. Sobrino-Cossio, Angelica Hernandez-Guerrero Gastroenterology, National Cancer Institute, Mexico City, Mexico; Cytogenetics, National Cancer Institute, Mexico City, Mexico Background: The sensitivity of EUS-guided cytology for the diagnosis of pancreatic adenocarcinoma is between 70 & O90%; among the identified factors that predict a positive result, the presence of a cytopathologist, number and passes and posible the type of needle have been identified as helpful. Aim: To study if the addition of FISH to cytology increases the sensitivity of EUS-guided FNA. Material & Methods: Consecutive patients with a pancreatic mass, sent for EUS-guided FNA to our Unit. An Olympus GF-UCT 160 echoendoscope and 22 gauge needles (EchoTip , Cook Medical), were used. Between 1-4 passes (median: 2) were performed for preparation of slides and cell block; 1 random slide was used for FISH analysis, which was performed using a commercially available kit (Urovision ). NO cytopathologist was present during the procedure. A total of 112 patients was calculated as the number needed to demonstrate at least a 10% increase in sensitivity, assuming an average of 80% sensitivity. A positive result was considered when either cytopathology or FISH alone or both were positive. Diagnostic values were calculated for Cytology, FISH and the combination; increase in sensitivity was the main variable. Inadequate specimens were purposely not included. The gold standard was considered to be: the surgical specimen, or a combination of CA 19-9 values, appropriate clinical and imaging picture plus compatible outcome on follow-up (FU). The study was approved by the IRB of our Institution. Results: A total of 105 patients were included; 16 were excluded for various reasons and analysis was performed on 89 patients. 49 were female, with a median age of 58 years (37-84); median FU was 4 months (1-12). Diagnostic values are shown in Table 1: A 13% increase in sensitivity was found, even when the calculated number was not reached. Conclusion: The addition of FISH analysis to EUS-guided FNA increases the sensitivity and positive results in patients with pancreatic adenocarcinoma. FISH could be used routinely, specially in settings without an onsite cytopathologist and with relatively few needle passes.