A Lower Cyst Fluid CEA Cut-Off Increases Diagnostic Accuracy In Identifying Mucinous Pancreatic Cystic Lesions

Abstract

Context Carcinoembryonic antigen analysis of pancreatic cyst fluid is the tumor marker of choice for preoperatively differentiating mucinous from non-mucinous cystic lesions. Objective We aim to determine the most accurate cyst carcinoembryonic antigen cut-off value for distinguishing mucinous cysts from non-mucinous cysts with a focus on discriminating intraductal papillary mucinous neoplasms. Methods The results of pancreatic cyst aspiration carcinoembryonic antigen levels from a single center were retrospectively collected and evaluated for a diagnosis of a mucinous cyst and an assessment of malignancy using surgical histology as the diagnostic standard in 86 patients. Results The median cyst carcinoembryonic antigen level (ng/mL) was significantly higher in mucinous cysts compared with non-mucinous cysts (218 vs. 4.4; P=0.0006) and in intraductal papillary mucinous neoplasms compared with non-mucinous cysts (135 vs. 4.4; P=0.0027). A cyst carcinoembryonic antigen cut-off of 30.7 ng/mL was most accurate (87.2%) for differentiating mucinous from non-mucinous cysts and specifically for differentiating intraductal papillary mucinous neoplasms from non-mucinous cysts (82.7%). Cyst carcinoembryonic antigen levels were not significantly different between malignant and non-malignant mucinous cysts (68.5 vs. 238.1; P=0.51). Conclusions Pancreatic cyst fluid carcinoembryonic antigen can accurately differentiate histologically verified mucinous lesions, including intraductal papillary mucinous neoplasms, from non-mucinous lesions with an optimal cut-off that is much lower than previously reported values. Cyst carcinoembryonic antigen levels are not a reliable predictor of malignancy. Image: Sensitivity and specificity curves of cyst fluid CEA levels for differentiating mucinous from non-mucinous cysts.