Plasma soluble urokinase-type plasminogen activator receptor (P-suPAR) in the diagnostics between malignant and non-malignant pancreatic lesions

Background: Soluble urokinase-type plasminogen activator receptor (suPAR) is a biomarker elevated in several inflammatory conditions and cancers. It has recently been shown to be elevated in pancreatic ductal adenocarcinoma (PDAC). Plasma suPAR (P-suPAR) predicts the severity of the disease in first acute alcohol-induced pancreatitis (AAP) and ten-year mortality after recovery from first AAP. According to our previous results, P-suPAR is not elevated in chronic pancreatitis (CP) and could possibly be used in distinguishing pancreatic cancer (PC) from CP. When imaging creates a suspicion of a pancreatic lesion, the distinction between malignant and non-malignant disease is crucial. Additional tools are needed, and we still lack a sufficiently sensitive and specific biomarker. Our aim was to further investigate whether preoperatively measured P-suPAR is beneficial in distinguishing between malignant and non-malignant pancreatic lesions. Methods: One hundred and seventy-six patients evaluated in Tampere University Hospital for pancreatic surgery for suspected malignant pancreatic lesion were recruited for the study. The final study group consisted of 113 patients. P-suPAR and other covariates were measured before the planned operation. Results: P-suPAR was significantly higher in patients with pancreatic cancer (PC) [median 4.1 (IQR 3.3–5.1) ng/mL] than in patients with non-malignant [3.3 (2.9–4.4) ng/mL; p = 0.012] histology. ROC curve analysis resulted in an AUC of 0.65 (95% CI 0.55–0.76); p = 0.007 and a cutoff value of 3.2 ng/mL. Crosstabulation yielded sensitivity of 82% and specificity of 43%. A combination of positive P-suPAR and elevated plasma carbohydrate antigen 19–9 (P-CA19-9) tests did not improve sensitivity but elevated specificity up to 86–88%. Conclusions: Preoperative P-suPAR is elevated in patients with PC compared to patients with a non-malignant pancreatic lesion. Combining P-suPAR with P-CA19–9 may improve diagnostic accuracy.