Prognostic Significance of Growth Factors and the Urokinase-Type Plasminogen Activator System in Pancreatic Ductal Adenocarcinoma Aiqun Xue, MSc,* Christopher J. Scarlett, PhD,* Christopher J. Jackson, PhD,Þ Barry J. Allen, DSc, FAPS,þ and Ross C. Smith, MD, FRACS* Objectives: To determine the diagnostic and prognostic significance of growth factors and the urokinase-type plasminogen activator (uPA) system in pancreatic ductal adenocarcinoma (PDAC) using a multi- gene assay. Methods: Messenger RNA (mRNA) expression of 15 genes from epidermal growth factor receptor, insulin-like growth factor (IGF), and uPA families were measured in 46 PDAC tissue samples using quantitative real-time reverse transcriptionYpolymerase chain reac- tion. These results were compared with those of the uninvolved adjacent (AP) tissue and benign mucinous cystadenomas (BMC). The mRNA expression was evaluated using logistic regression and re- ceiver operating characteristic area under the curve (ROC AUC) ana- lyses. Their relationship with prognosis was tested by Cox regression multivariate analysis. Results: All genes were overexpressed in most of the PDAC tissue. When compared with AP tissue, the median expression values for IGFYbinding protein 3 (IGFBP-3) and uPA receptor (uPAR) was 9.8- and 9.6-fold, respectively. Expression levels of uPA, uPAR, IGF-I, and IGFBP-3 mRNA were significantly greater in PDAC than in BMC. The IGFBP-3 mRNA expression demonstrated greatest ROC AUC values for PDAC versus AP tissue (ROC AUC, 0.745; 95% confidence interval [CI], 0.65Y0.86); whereas ROC AUC values were greatest for uPAR when PDAC was compared with BMC (ROC AUC, 0.846; 95% CI, 0.76Y0.94). The combination of uPA, uPAR, and IGF-I significantly improved discriminatory power (ROC AUC, 0.965; 95% CI, 0.93Y1.00). The IGFBP-3, uPA, plasminogen ac- tivator inhibitor-2, and International Union Against Cancer stage had a significant influence on survival, but the effect of IGFBP-3 was lost after multivariate stepwise analysis. Conclusions: These results indicate that there is an influence of IGF system in tumor progression from BMC to PDAC, whereas the uPA/ uPAR system has the greater influence on survival in PDAC. Key Words: pancreatic ductal adenocarcinoma, epidermal growth factor receptor family, insulin-like growth factor family, urokinase-type plasminogen activator system (Pancreas 2008;36:160Y167) P ancreatic ductal adenocarcinoma (PDAC) is one of the most formidable malignancies 1Y4 and is highly resistant to current therapies. 5,6 Current diagnostic and prognostic techniques such as fine-needle aspiration biopsies are limited in their ability to detect PDAC in its early stages. Biomarkers offer a new opportunity for early detection of PDAC and may lead to new methods of diagnosing and treating PDAC before it metastasizes. A growing body of evidence suggests that overexpres- sion of various genes may lead to oncogenesis, transformation, tumor metastases, and invasion of PDAC cells. Altered genes include the members of the insulin-like growth factor (IGF), epidermal growth factor receptor (EGFR), and urokinase-type plasminogen activator (uPA) families. The IGF family is composed of IGF-I and IGF-II, their signaling receptors IGF- IR and IGF-IIR, as well as the 6 high-affinity IGF-binding proteins (IGFBP-1 to IGFBP-6) and 4 low-affinity IGFBPs (IGFBP-7 to IGFBP-10). 7,8 This family plays an important role in cancer cell proliferation, adhesion, and inhibition of apoptosis. 9 The EGFR family has 4 distinct EGFRsV HER-1 (EGFR or ErbB1), HER-2 (ErbB2), HER-3 (ErbB3), and HER-4 (ErbB4) 10,11 and plays a critical role in signal transduction involving activation of a cascade of intracel- lular enzymeYregulated pathways in pancreatic cancer. 12Y15 The uPA system, one of 2 major protease systems, includes uPA, its receptor uPAR, and 2 inhibitors, plasminogen activator inhibitor-1 (PAI-1) and PAI-2 (PAI-2). This path- way plays a key role in modulating plasminogen activation and promoting local invasion and distant metastasis in pancreatic cancer. 16 There are currently no markers for PDAC with sufficient sensitivity and specificity. Although many genes are over- expressed in PDAC, they are often elevated in other non- malignant pancreatic disorders, thus they lack the required specificity of diagnostic and prognostic potential. 7,15,17 This study uses receiver operating characteristic (ROC) analysis to compare the strength of relationship of expression of different mRNAs in cancer tissue with that of controls. The 15 genes studied are members of the IGF, EGFR, and uPA families. ORIGINAL ARTICLE 160 Pancreas & Volume 36, Number 2, March 2008 Received for publication December 18, 2006; accepted August 2, 2007. From the *Department of Surgery, The University of Sydney, Sydney; †Sutton Research Laboratories, Kolling Institute of Medical Research, Royal North Shore Hospital, St Leonards; and ‡Centre for Experimental Radiation Oncology, Cancer Care Centre, St George Hospital, Kogarah, New South Wales, Australia. This study was supported by the Cancer Surgery Research Foundation. Reprints: Ross C. Smith, MD, FRACS, Department of Surgery, The University of Sydney, Royal North Shore Hospital, St Leonards, NSW 2065, Australia (e-mail: rsmith@med.usyd.edu.au). Copyright * 2008 by Lippincott Williams & Wilkins Copyright @ 2008 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.