Circulating Thrombospondin-2 enhances prediction of malignant intraductal papillary mucinous neoplasm

Background: IPMNs are cystic pancreatic lesions with variable malignant potential. Thrombospondin-2 (THBS2)-an endogenous, anti-angiogenic matrix glycoprotein-may modulate tumor progression. We hypothesized that circulating levels of THBS2 could aid in preoperative prediction of malignant IPMN. Methods: Preoperative serum/plasma samples were procured from patients undergoing surgery. Circulating levels of THBS2 were measured (enzyme-linked immunosorbent assay) and compared to surgical pathology IPMN dysplastic grade. Results: 164 patients underwent THBS2 testing (100 Low/Moderate-IPMN; 64 High-Grade/Invasive-IPMN). Circulating THBS2 (mean +/- SD) was greater in High-Grade/Invasive-IPMN than Low/Moderate-grade IPMN (26.6 +/- 12.7 ng/mL vs. 20.4 +/- 8.2 ng/mL; P < 0.001). THBS2 (AUC = 0.65) out-performed CA19-9 (n = 144; AUC = 0.59) in predicting IPMN grade. The combination of THBS2, CA19-9, radiographic main-duct involvement, main-duct diameter, age, sex, and BMI (AUC 0.82; n = 137) provided a good prediction model for IPMN grade. Conclusion: Circulating THBS2 is correlated with IPMN dysplasia grade. THBS2 alone did not strongly predict IPMN grade but rather strengthened prediction models for High-Grade/Invasive IPMN when combined with other clinical/biomarker data. (C) 2018 Elsevier Inc. All rights reserved.