Diagnostic utility of clinical and biochemical parameters in pancreatic head malignancy patients with normal carbohydrate antigen 19-9 levels

Background: Carbohydrate antigen (CA)19-9 that is the most widely used biomarker for pancreatic cancer has certain limitations in diagnosis, which results in a tough job to distinguish pancreatic cancer from benign tumors with normal CA19-9. The aim of this study was to investigate the diagnostic utility of clinical parameters and serum markers in patients with pancreatic head masses but without elevated CA19-9. Methods: Retrospectively, 106 (69 malignant, 37 benign) of 487 patients admitted for pancreatic head masses were enrolled with CA19-9 level of 37u/ml. Clinical parameters and serum biomarkers were assessed. Among the patients with pancreatic head mass, male individuals (p=0.025) and elder individuals (p 0.001) were more likely to have cancer; and cancer patients were more likely to present with abdominal-pain (p=0.023), weight-loss (p=0.013) and jaundice (p 0.001). Serum bilirubin levels among malignancies, including total bilirubin (p 0.001), direct bilirubin (p 0.001) and indirect bilirubin (p 0.001), were considerably higher than those of benign ones. Logistic regression further concluded that age-distribution, abdominal-pain and direct-bilirubin were three independent factors correlating with final diagnosis. However, CEA (p=0.156) was not sufficient enough to exclude pancreatic cancer. Conclusions: In patients with pancreatic head masses and CA19-9 of 37u/ml, age-distribution, abdominal-pain and direct bilirubin might be helpful in differential diagnosis. CEA was insufficient for exclusion of malignancy.