Diagnostic yield of bile duct brushings for cholangiocarcinoma in primary sclerosing cholangitis: a systematic review and meta-analysis

Background: The most ominous adverse event of primary sclerosing cholangitis (PSC) is development of cholangiocarcinoma (CCA). There is a wide variation in the reported diagnostic yield of bile duct brush cytology in PSC strictures.

Objective: To determine the diagnostic utility of biliary brush cytology for CCA detection in patients with PSC.

Design: Meta-analysis. Systematic search of PubMed, EMBASE, Web of Science, and the Cochrane Library for relevant studies published up to December 2012.

Setting: Meta-analysis of diagnostic parameters.

Patients: A total of 747 patients in studies (both retrospective and prospective) in which histopathologic correlation of CCA was available.

Intervention: Meta-analysis. Construction of 2 × 2 contingency data.

Main outcome measurements: Sensitivity, specificity, likelihood ratio, and pooled diagnostic odds ratio.

Results: The search yielded 54 studies of which 11, involving 747 patients, were included in our meta-analysis. The pooled sensitivity and specificity of bile duct brushings for a diagnosis of CCA in patients with PSC were 43% (95% confidence interval [CI], 35%-52%) and 97% (95% CI, 95%-98%), respectively. The pooled diagnostic odds ratio to detect CCA was 20.23 (95% CI, 8.75-46.79). The heterogeneity indices of χ(2) statistics, I(2) measure of inconsistency, and the Cochran Q test were 0.156, 14.4, and 30.5%, respectively. Visual inspection of the funnel plot showed low potential for publication bias.

Limitations: Inclusion of low-quality studies, study heterogeneity.

Conclusion: Our study suggests that bile duct brushing is a simple and highly specific technique for detection of CCA in patients with PSC. However, the modest sensitivity from bile duct brushing precludes its utility as a diagnostic tool for early detection of CCA in patients with PSC.