To evaluate the reliability and accuracy of Cytokeratin-19-fragment (CYFRA21-1) in the diagnosis of intrahepatic cholangiocarcinoma (ICC) based on literature meta-analysis and the diagnostic efficacy and clinical application of CYFRA21-1 in ICC.

MEDLINE, China National Knowledge Infrastructure Library and other databases were used to base the inclusion and exclusion criteria. In addition, relevant data from studies on CYFRA21-1 were used to diagnose ICC individually or in combination was retrieved for meta-analysis. Research papers were manually screened by two independent researchers. The selected papers were evaluated by QUADAS-2 standard. The SROC was plotted according to the extracted data combined with the results of diagnosis to evaluate the diagnostic efficiency of CYFRA21-1 in ICC.

Six articles with an overall sample size of 731 cases, including 217 cases in the positive group and 514 cases in the control group, met the inclusion criteria and were included for the systematic review. When CYFRA21-1 was used for ICC diagnosis, the pooled diagnostic indices were as follows: sensitivity 0.81 (95%CI: 0.75–0.86); specificity, 0.86 (95%CI: 0.82–0.89); positive likelihood rate, 4.72 (95%CI: 2.02–11.02); negative likelihood ratio, 0.25 (95%CI: 0.19–0.33); diagnostic odds ratio, 27.43 (95%CI: 13.20–57.00); and area under the ROC curve, 0.904 (SE = 0.0171).

CYFRA21-1 is of certain value in the diagnosis of intrahepatic cholangiocarcinoma.