Pancreatic juice CEA during SPACE for pancreatic duct stenosis: diagnostic and exploratory risk stratification value

This study evaluated whether pancreatic juice carcinoembryonic antigen (PJ-CEA) measurement during serial pancreatic juice aspiration cytologic examination (SPACE) enhanced diagnostic accuracy and was associated with subsequent pancreatic cancer (PC) diagnosis, especially in cytology-negative patients.

We retrospectively analyzed 206 patients undergoing both SPACE and PJ-CEA testing. Patients were classified into definitive diagnosis (intraductal papillary mucinous neoplasm [IPMN], non-malignant controls, or PC) and non-definitive diagnosis groups. Because PJ-CEA may be elevated in IPMN regardless of malignant potential, the cutoff for distinguishing PC from non-malignant controls was determined by ROC analysis after excluding IPMN cases from the definitive diagnosis group. Diagnostic performance was compared for SPACE alone, PJ-CEA alone, and their combination. In the non-definitive diagnosis group, cumulative PC incidence was compared between high and low PJ-CEA subgroups using Kaplan-Meier analysis.

The optimal PJ-CEA cutoff was 7.9 ng/mL (AUC 0.924). In the definitive diagnosis group, sensitivity increased from 51.2% with SPACE alone to 86.0% when combined with PJ-CEA (p < 0.001). In the non-definitive diagnosis group, elevated PJ-CEA (≥ 7.9 ng/mL) was associated with subsequent PC (HR 11.7, p = 0.025), with a higher cumulative incidence in the high PJ-CEA subgroup (p = 0.019). These findings are based on a limited number of events and should be interpreted as exploratory, requiring external validation.

After excluding radiologically identifiable IPMN, PJ-CEA measurement during SPACE may improve diagnostic sensitivity for PC and may provide preliminary information for exploratory risk stratification in cytology-negative patients. Further external validation is required before PJ-CEA can be used to guide re-testing and surveillance strategies.