Diagnostic value of cell-free DNA to biliary tract cancers: a meta-analysis

Objective·To comprehensively evaluate the diagnostic accuracy of cell-free DNA (cfDNA) to biliary tract cancer (BTC), and provide a basis for better clinical application.Methods·Clinical studies on the diagnostic value of cfDNA to BTC were collected by searching eight databases from inception to April 2023. The studies were selected according to the inclusion and exclusion criteria, and then data was extracted. The threshold effects were assessed with Spearman′s rank correlation analysis, and heterogeneity among the included studies was analyzed by using Cochran′s Q test and I2 test. A bivariate mixed-effects model was fitted, and statistics such as overall sensitivity, specificity, and area under the curve (AUC) were calculated to determine the diagnostic performance. The subgroup analyses were carried out based on the study type, sample size, detection method, sample source, and diagnostic reference standard.Results·A total of 28 diagnosis tests were included, all of which were evaluated as medium-high quality by using Diagnostic Accuracy Studies Tool Version 2 (QUADAS-2). The presence of threshold effects was found by using the Spearman rank correlation analysis. The pooled sensitivity was 0.80 (95%CI 0.67‒0.88), and specificity was 0.96 (95%CI 0.92‒0.98), positive likelihood ratio (PLR) was 22.7 (95%CI 9.4‒55.2), negative likelihood ratio (NLR) was 0.21 (95%CI 0.12‒0.36), and diagnostic odds ratio (DOR) was 108 (95%CI 31‒374), respectively. The AUC of the summary receiver operating characteristic (SROC) curve was 0.96 (95%CI 0.94‒0.98), demonstrating the high accuracy of cfDNA in the diagnosis of BTC. The results of subgroup analyses suggested that the accuracy and sensitivity of choosing different testing methods and sample sources varied.Conclusion·The detection of cfDNA has high sensitivity and specificity in diagnosing BTC, and is suitable for the patients suspected to be malignant after screening with imaging tests and conventional tumor markers. However, the standardization and uniformity of detection methods and sample sources still need to be further standardized by conducting clinical studies on a wider population.