Carcino Embryonic Antigen and long-term follow-up of mucinous pancreatic cysts including intraductal papillary mucinous neoplasm

Background and aims: The utility of Carcino Embryonic Antigen (CEA) in differentiating malignant from benign pancreatic cysts is controversial. We sought to examine the role of CEA in differentiating benign from malignant cysts and its utility in progression of cyst size in follow-up. Methods: Retrospective chart review of patients who underwent Endoscopic Ultrasound with Fine Needle Aspiration for mucinous cysts between 1998 and 2010. CEA was measured in benign and malignant mucinous cysts. Coefficient of determination (R²) was used to measure the association between change in cyst size and CEA. Mann-Whitney test was used to compare the median values of CEA. Results: 143 patients (38.4% males) were included (mean age 68.9±0.8 years). 105 patients had intra-cystic CEA measured. 63 patients underwent surgery while 80 patients were in the follow-up group. In the surgical group, median CEA value for benign and malignant mucinous neoplasms was 796 and 438ng/ml, respectively (p=0.79). The median follow-up was 21 months. There was no correlation between CEA level and progression in cyst size in patients who had >6 months of follow-up, R²=0.0002. Malignant transformation was observed in 5 (5.9%) patients. Conclusion: CEA level was not predictive of malignant cyst nor cyst size progression over follow-up.