Mo1494 Pretest Probability and Diagnostic Accuracy of Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA) for Pancreatic Adenocarcinoma At a Tertiary Care Oncology Center: a 12 Year Experience

Pretest Probability and Diagnostic Accuracy of Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA) for Pancreatic Adenocarcinoma At a Tertiary Care Oncology Center: a 12 Year Experience Somashekar G. Krishna*, Abhik Bhattacharya, Harshad S. Ladha, Amanpal Singh, William A. Ross, Manoop S. Bhutani, Jason B. Fleming, Jeffrey H. Lee Department of Gastroenterology, Hepatology and Nutrition, The Ohio State University Medical Center, Columbus, OH; Department of Gastroenterology, Hepatology and Nutrition, University of Texas at MD Anderson Cancer Center, Houston, TX Background: Pancreatic adenocarcinoma (PAC) represents 90% of all pancreatic malignancies. There are several studies investigating diagnostic accuracy of EUSFNA for pancreatic adenocarcinoma. However the study populations are mixed and with limited numbers. Aims: To further clarify the pretest probability and diagnostic accuracy of EUS-FNA for pancreatic adenocarcinoma at a tertiary oncology institute where patient referrals are primarily for non-benign pancreatic diseases. Methods: A retrospective review of the EUS database from January 2000 to December 2011, inclusive of consecutive referrals for evaluation of pancreatic lesions. Demographic information, patient’s history, computed tomography of abdomen and pelvis (CT-AP), FNA and surgical pathology were reviewed. Results: A total of 1333 EUS studies were performed for suspected pancreatic lesions (solid and cystic) of which 1108 patients underwent EUS-FNA. Among these, 772 (69.7%) had solid pancreatic lesions (SPLs). The overall sensitivity, specificity, positive predictive value (PPV) and accuracy of EUS-FNA for diagnosis of malignant lesions among SPLs was 95.7%, 91.7%, 99.7%, and 95.6% respectively. On-site cytology was available for all cases. Among the 1108 patients who underwent pancreatic EUS-FNA, PAC was diagnosed in 543 (49%) patients. The most common presentation was a solitary SPL (table 1). Among SPLs, the sensitivity, specificity, PPV and accuracy of EUS-FNA for diagnosis of PAC was 99.8%, 93.7%, 97.5% and 98.1% respectively.For patients presenting with SPLs, univariate analysis revealed that increasing age, history of diabetes and smoking, and symptoms of weight loss, abdominal pain and diarrhea were significantly associated with adenocarcinoma (table 2). Increasing lesion size, location of lesion in the head of the pancreas, CT evidence of arterial invasion and CT/EUS evidence of main pancreatic duct (MPD) dilation were also significantly associated with PAC (table 2). By multivariate analysis (table 3), factors significantly predicting PAC among SPLs included increasing age (OR 1.08, 95% CI 1.04, 1.12, p 0.001), weight loss (OR 3.5, 95% CI 1.53, 7.87, p 0.003), elevated CA 19-9 (OR 6.22, 95% CI 3.07, 12.58, p 0.001), EUS or CT evidence of dilation of the MPD (OR 4.28, 95% CI 2.10, 8.72, p 0.001), and CT-AP evidence of arterial invasion (OR 18.1, 95% CI 3.90, 83.75, p 0.001). Conclusion: EUS-FNA is highly accurate for diagnosis of malignancy and PAC in SPLs. The pretest probability of finding PAC is highest with evidence of arterial invasion, an elevated CA 19-9, dilation of MPD, history of weight loss and increasing age of the patient. With 3 out of 5 of these factors present, the PPV for PAC is 91.2%.