T1370 Elevated Cyst Fluid Carcinoembryonic Antigen (CEA) Level is Not a Accurate Predictive Marker of Invasive Cancer in Patients With Intraductal Papillary Mucinous Neoplasm (IPMN) of the Pancreas

Abstract

Background: In the preoperative management of cystic lesions of the pancreas, an elevated CEA level >192ng/ml has been proven to be the most accurate marker to differentiate between a mucinous or nonmucinous neoplasm. One factor in the decision to operate on these cystic lesions is determined on the degree of CEA elevation. Whether CEA level results can be applied to IPMN’s has not been well studied, but given the mucinous nature of these neoplasms, management decisions are partially based on the degree of cyst fluid CEA level elevation. Aim: The aim of this study was to determine whether a markedly elevated CEA level was predictive of invasive cancer in patients with surgically resected IPMNs. Methods: For this study we identified all patients from our IRB approved Pancreatic IPMN Surgical Database who have undergone an Endoscopic Ultrasound(EUS) procedure at H. Lee Moffitt Cancer Center. 87 patients were included in the analysis with surgical resections from 2000-2009. From this population we included all patients who had preoperative cyst fluid CEA levels obtained by EUS-Guided FNA recorded. One-way ANOVA was performed to examine the differences of CEA levels among pathologic stages. Results: 47 patients (32 men) underwent preoperative EUS-FNA and surgical resection of an IPMN. The mean level of CEA increased as the pathology worsened from no dysplasia (adenoma) to high-grade dysplasia (Carcinoma in situ). Surprisingly, once invasive cancer developed the CEA level markedly decreased to levels comparable to the most benign surgical pathology. Furthermore, there was no difference in CEA levels with statistical significance between pathologic stages (p = 0.35). The Fluid CEA levels and corresponding surgical pathologic diagnoses are summarized in the table below. Conclusion: Based on this retrospective study, a markedly elevated cyst fluid CEA level was not an accurate predictor of invasive cancer in surgically resected IPMNs. In contrast, the appearance of invasive cancer in an IPMN lesion is associated with a decline in mean CEA level and there was no statistical significant difference in the CEA levels between the pathologic groups. Therefore the decision not to resect a cystic lesion should not be based solely on the observation that the CEA is low. Larger studies are needed to better define the role of cyst fluid CEA level in the management of pancreatic IPMNs.