Pancreatic Cystic Lesions: Is Fluid Glucose Better Than Carcinoembryonic Antigen?

Differentiating pancreatic mucinous from nonmucinous cysts can be challenging, and the pancreatic cyst fluid (PCF) carcinoembryonic antigen (CEA) level has suboptimal accuracy. Adjunct tests, such as molecular testing, histology using microbiopsy forceps, and needle-based confocal laser endomicroscopy, can help but are not universally available and can be expensive. Preliminary data on PCF glucose levels have been promising for distinguishing mucinous from nonmucinous pancreatic cysts. This meta-analysis aimed to compare the accuracy of glucose level with CEA in PCF for diagnosing mucinous cysts.

The study included 2083 patients with PCL CEA levels and 275 patients with glucose levels; gold standard surgical pathology was also included. The glucose level (<50 mg/dL) was superior to CEA (>192 ng/mL) in identifying mucinous cysts, with sensitivities of 0.90 (95% confidence interval [CI], 0.85-0.94) and 0.67 (95% CI, 0.65-0.70), specificities of 0.82 (95% CI, 0.72-0.89) and 0.80 (95% CI, 0.76-0.83), and areas under the receiver operating characteristic curve (AUC) of 0.96 and 0.79, respectively. With the high sensitivity and rare false-negative results, a PCF glucose level >50 mg/dL is an excellent biomarker to exclude a mucinous cyst. The study was limited by considerable heterogeneity in the reported studies of CEA and limited sample size in evaluating PCF for glucose.