CA 19-9 to differentiate benign and malignant masses in chronic pancreatitis: Is there any benefit?

Background: The role of the tumor marker CA 19-9 in differentiating benign from malignant masses in chronic pancreatitis has not been extensively studied. Aim: This study aims at assessing the accuracy of CA 19-9 in differentiating inflammatory head masses in chronic pancreatitis from superimposed carcinomas on chronic pancreatitis. Methods: The data of 84 consecutive patients who had mass lesions in chronic pancreatitis were analyzed to determine the sensitivity, specificity and predictive values at cut-off values of 37, 100, 200 and 300 U/mL. Receiver operating characteristic (ROC) curves were used to assess the sensitivity and specificity. Results: There were 50 benign masses and 34 malignancies. The overall sensitivity and specificity of CA 19-9 for cancer was 68% and 70%, respectively. There was a higher positivity of CA 19-9 in cancers than in benign masses (23/34; 68% versus 15/50; 30%, P<0.01) with cut-off values of 37 U/mL. Higher positivity rates were obtained in cancers using other cut-off values such as 100, 200 and 300 U/mL. Values over 300 U/mL were 100% specific for malignancy, but occurred in only 5 (of whom had distant metastases) of 34 patients. Conclusion: CA 19-9 level in excess of 300 U/mL in mass lesions in chronic pancreatitis was always indicative of malignancy. © Indian Society of Gastroenterology 2009.