Significance of the Expression of the Growth Factor Pleiotrophin in Pancreatic Cancer Patients

Purpose: Recently, we found that pleiotrophin (PTN) acts as a rate-limiting autocrine growth factor in pancreatic cancer cells. The aim of this study was to determine the expression pattern of PTN in pancreatic cancer and to analyze the clinical significance of PTN in pancreatic cancer patients. Experimental Design: We compared PTN expression in malignant ( n = 24), inflammatory ( n = 13), and normal ( n = 14) pancreatic tissues using immunohistochemistry and in situ hybridization and determined PTN serum levels in pancreatic cancer patients ( n = 77), in patients suffering from chronic pancreatitis ( n = 21), and in healthy volunteers ( n = 28). Two-year survival rates were determined for pancreatic cancer patients in relation to serum levels of PTN. Results: The frequency of PTN expression increased from normal tissue (7%) to inflammatory (34%) and pancreatic cancer tissues (67%; P < 0.05). Compared with a healthy control group, we found elevated PTN serum levels in 30% of patients with chronic pancreatitis (mean, 143 ± 55 pg/ml) and in 53% of pancreatic cancer patients (mean, 200 ± 29 pg/ml; P < 0.05). Elevated serum levels of PTN dropped in patients after successful tumor resection but were unaffected when only palliative surgery was performed ( P < 0.0001). High preoperative serum PTN levels correlated with a worse 2-year survival ( P < 0.05). Conclusions: This study supports the clinical significance of PTN for the malignant progression of pancreatic cancer.