Establishment and validation of a nomogram containing cytokeratin fragment antigen 21-1 for the differential diagnosis of intrahepatic cholangiocarcinoma and hepatocellular carcinoma

Abstract

Abstract Background Our study aimed to develop a nomogram, including cytokeratin fragment antigen 21 − 1 (CYFRA21-1) to aid in the differential diagnosis of patients with intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC). Methods This study included a total of 487 patients diagnosed with ICC and HCC at Qilu Hospital of Shandong University. They were further divided into a training cohort and a validation cohort based on whether the data was collected retrospectively or prospectively. Univariate and multivariate analyses were used to select variables for the nomogram. The discrimination and calibration of the nomogram were assessed using the area under the receiver operating characteristic curve (AUC) and calibration plots. The net benefits of the nomogram at different threshold probabilities were evaluated using decision curve analysis (DCA). Results Six variables, including CYFRA21-1, were selected to establish the nomogram. A satisfactory discriminative ability of the nomogram was indicated by AUC (0.979 of training cohort, 0.991 of validation cohort). Hosmer-Lemeshow test and the calibration plots showed favorable consistency between the prediction of the nomogram and actual observations. Furthermore, DCA demonstrated that the nomogram was clinically useful and had better discriminative ability than the model without CYFRA21-1 and the model consisted of logarithm of alpha-fetoprotein (Log AFP) and logarithm of carbohydrate antigen 19–9 (Log CA19–9). Conclusions This study developed and validated a nomogram, including CYFRA21-1 that can assist clinicians in the differential diagnosis of ICC and HCC in patients.