8%) such as choledocholithiasis, gallbladder cancer and cholangiocarcinoma. Finally, CA 19-9 serum levels alone cannot differentiate between benign, precursor lesions and malignant pancreatic conditions such as acute and chronic pancreatitis, intraductal pancreatic mucinous neoplasms
(IPMN), pancreatic intra-epithelial neoplasia (PANIN) and pancreatic cancer, as the former are also associated with elevated CA 19-9 serum levels in 10-50% of cases (69-75). Table 6 False positive elevations of the CA 19-9 serum level have been noted in a variety of pathological conditions, most notably in the presence of obstructive Inhibitors,research,lifescience,medical jaundice. As such, CA 19-9 serum levels cannot be used to differentiate benign from malignant pancreatic … Hyperbilirubinemia is also a significant confounding factor since it is associated with an increased Inhibitors,research,lifescience,medical CA 19-9 serum level in cases of both benign and malignant biliary mTOR inhibitor obstruction (8,9,12,20). Although CA 19-9 serum levels in the presence of obstructive jaundice may have higher sensitivity,
it is at the cost of decreased specificity and accuracy. Mery et al. studied 548 patients with obstructive jaundice and Inhibitors,research,lifescience,medical reported a higher CA 19-9 serum level among pancreatic cancer patients compared to those with other hepatobiliary malignancies or benign diseases. These authors noted that by increasing the cut-off level for CA 19-9 serum level from 37 to 90 U/mL they were better able to differentiate malignant hepatobiliary diseases Inhibitors,research,lifescience,medical from benign diseases (sensitivity 86% vs. 61% and specificity 39% vs. 86%) (75). Kau et al. studied 86 resectable and 57 unresectable pancreatic cancer patients and reported that a mean CA 19-9 serum levels of 191±6 U/mL and 1203±400 U/mL was associated with serum bilirubin levels of <7.3 mg/dL or >7.3 mg/dl respectively (31). Ong et al. studied 83 patients presenting with abnormal CA19-9 serum levels and radiological or clinical features suggestive of hepato-biliary-pancreatic
(HPB) malignancy who were subsequently found to have benign disease. On multivariate analysis, these authors reported that hyperbilirubinemia (serum bilirubin >2 mg/dL) Inhibitors,research,lifescience,medical was an independent factor predictive of CA 19-9 serum level (P=0.028) (76,77). Biliary drainage which results in a decrease in CA 19-9 serum levels may suggest benign conditions. Marrelli et al. studied 128 patients admitted with obstructive ALOX15 jaundice including 87 patients with pancreatico-biliary malignancy and 42 patients with benign diseases. CA 19-9 serum levels were elevated in 61% of benign causes and 86% of malignant causes, which resulted in a reduction in accuracy to 61%. Following biliary drainage CA 19-9 serum levels decreased in nearly all benign cases (41 of 42 patients, 98%) but in only 19 out of 38 (50%) patients with malignant biliary obstruction (78). Kau et al. reported a 40% reduction in CA 19-9 serum levels after relief of malignant biliary obstruction.