Validation of IL-7R as an Immunological Biomarker for Human Pancreatic Ductal Adenocarcinoma

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer for which no early diagnostic method is available. The immune surveillance hypothesis suggests that the immune system plays crucial roles in tumor development and progression. We validated a PDAC-specific bi-omarker derived from peripheral blood mononuclear cells (PBMCs) to facilitate early PDAC diag-nosis. mRNA levels of interleukin-7R (IL-7R), reportedly a potential immunological marker for PDAC, were measured in PBMCs isolated prospectively from healthy controls (n = 100) and patients with PDAC (n = 135), pancreatic cysts (n = 82), chronic pancreatitis (n = 42), acute pancreatitis (n = 47), and other malignancies (n = 116). The IL-7R level was significantly higher in patients with PDAC than in healthy controls, patients with benign pancreatic disease, and patients with other malignan-cies. As diagnostic parameters, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for IL-7R were 58.5%, 92%, 90.8%, 62.2%, and 72.8%, respectively. The area under the receiver operating characteristic curve (AUROC) was 0.766. IL-7R levels did not dif-fer between resectable and unresectable PDAC cases. The combined measurement of IL-7R and car-bohydrate antigen 19-9 (CA19-9) significantly improved the diagnostic parameters and AUROC compared with the use of IL-7R or CA19-9 alone. IL-7R is significantly upregulated in PBMCs in patients with PDAC, and it may be a novel diagnostic marker for PDAC. The combined use of IL-7R and CA19-9 enhanced the diagnostic performance. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.