CA19.9 in differentiating benign and malignant obstructive jaundice

Serum carbohydrate antigen 19-9 (CA 19-9), a tumour marker for malignancies of the hepatobiliary tract and pancreas, frequently elevated in a number of non-malignant conditions that are associated with jaundice. The CA 19-9 tends to normalize the following restoration of biliary drainage. Sixty three patients presented with obstructive jaundice on the basis of clinical and imaging methods with elevated CA 19-9 were studied. Diagnostic accuracy of CA19-9 in the detection of malignancy was estimated by the receiver operating characteristic (ROC) curve. Median value of CA 19-9 in malignant cases was higher (1000 U/ml) than benign cases (93 U/ml) (p=0.001). After biliary drainage serum CA19-9 levels normalized in 15(50%) benign and 1(3%) malignant cases (p=0.001). The AUC of CA 19-9 was 0.825. Diagnostic accuracy of CA 19-9 was observed more at cut off value 200 U/ml. Deranged CA19-9 is frequently observed in benign conditions with jaundice and shown to normalize following improvement of biliary drainage. Caution is necessary in the interpretation of an elevated serum CA 19-9 value as a marker for malignancy, especially in patients with benign cholestasis.