Serum total sialic acid in cholangiocarcinoma patients: an ROC curve analysis

Objectives: This study was undertaken to establish the diagnostic utility of serum total sialic acid (TSA) for patients with cholangiocarcinoma (CCA). Design and methods: Serum TSA was determined in 89 histologically confirmed CCA patients, 38 with benign hepatobiliary diseases (BHD) and 43 healthy persons. To check whether the test could adequately discriminate between these groups, complete statistical Receiver Operating Characteristic (ROC) curves were analyzed. Results: The mean value of serum TSA in CCA patients (2.75 ± 0.67 mmol/L) was significantly higher than that in the BHD (2.33 ± 0.69 mmol/L p< 0.002) and healthy persons (1.89 ± 0.46 mmol/L p< 0.001) groups. The areas under the ROC curves were 0.6699 and 0.8558, respectively. A cut-off value of 2.33 mmol/L discriminated between the CCA, BHD and healthy groups with a sensitivity of 71.9% and a positive predictive value range of 80 to 89%. Conclusion: Determination of TSA yielded high diagnostic values for differentiating between CCA, BHD and healthy persons. The determination of serum TSA would be most useful as an adjunct diagnosis rather than an early detection and screening tool because of the apparent nonspecificity of SA to a given disease.