Prognostic and diagnostic value of circulating IGFBP2 in pancreatic cancer

Insulin-like growth factor binding protein 2 (IGFBP2) is overexpressed in tumor tissues of several malignancies, including pancreatic cancer. Because of its role in tumor progression, IGFBP2 has been investigated as a tumor biomarker. However, little is known about its utility in pancreatic cancer. Plasma IGFBP2 levels were determined using enzyme-linked immunosorbent assay in 75 patients with pancreatic ductal adenocarcinoma (PDAC), 73 matched healthy controls, and 17 chronic pancreatitis patients. Our results showed that the plasma IGFPB2 level was significantly higher in PDAC patients than in patients with chronic pancreatitis and healthy controls. At a cut-off value of 333.9 ng/mL, the specificity and sensitivity were 78.08 and 65.33%, respectively. IGFBP2 level alone did not outperform carbohydrate antigen 19-9 (CA19-9) in diagnostic accuracy, but it successfully identified 9 out of 24 PDAC patients who were misidentified by CA19-9. The combination of IGFBP2 and CA19-9 was more accurate in the detection of PDAC than CA19-9 alone. IGFBP2 was more accurate than the other in discriminating between chronic pancreatitis and PDAC. Plasma IGFBP2, rather than CA19-9, was higher in the new-onset diabetes, lymph node involvement, and distant metastasis subgroups. IGFBP2 level was notably higher in stage IV cases than in stage I/II or stage III disease. However, CA19-9 did not show a difference between stages. After adjusting for lymph node involvement and distant metastasis, plasma IGFBP2 was identified as an independent prognostic marker for PDAC. The median survival time for patients with an IGFBP2 level ≥333.9 ng/mL was significantly shorter than that for patients with an IGFBP2 level <333.9 ng/mL. Marked elevation of plasma IGFBP2 in PDAC is associated with poorer survival. IGFBP2 may be considered as a supplementary biomarker for the diagnosis and prognostic prediction in Chinese pancreatic cancer patients.