Outcomes of Different Methods for Analysis of Biliary Brush Cytology and of Factors Associated with Positive Diagnosis in an Age-Dependent Retrospective Review

Background and Aims: Brush cytology during endoscopic retrograde cholangiopancreatography (ERCP) is the most frequently used strategy for obtaining a tissue sample from an indeterminate biliary stricture. A recent study reported that age is a factor associated with positive yields, but further analysis of how age influences the results was lacking. We aimed to evaluate clinical effectiveness of biliary cytology and prognostic factors for a positive outcome, especially age. Methods: This study was a single-center, retrospective, clinical study of 77 consecutive patients who underwent brush cytology during ERCP to obtain a diagnosis of an indeterminate biliary stricture. We compared 2 routine cytology techniques: A (smear); B (centrifugation of the cytological material collected and the cut-off brush + cell block when sufficient amount of material was available). The data were collected aiming to compare the accuracy of the different techniques used and the prognostic factors affecting the outcome, with a particular focus on age. The yield for brush cytology was compared with the gold standard defined as either definitive histology or the long-term clinical course. Resultados: a acuidade global dos diferentes metodos foi 75.3%. A sensibilidade foi 52.5%, a especificidade foi 100%, VPP foi 100% e o VPN foi 66.1%. Apesar de nao ser estatisticamente definitivo existiu maior acuidade do metodo B, em comparacao com o A (80.4 vs. 65.4%; p = 0.153). A analise multivariada por regressao logistica mostrou que a menor idade e o unico fator de prognostico independente associado a um resultado positivo (OR: 0.95; 95% CI: 0.90–0.99; p = 0.039). As curvas ROC para a idade apresentaram um valor para a AUC de 68.2%. O indice de Youden, determinou que os 69 anos seriam o “cutoff” ideal para a idade. Conclusions: In this series, the accuracy of routine biliary brush cytology was not equal for all methods and ages; in particular, younger patients (below 69 years) tended to have a higher probability of a correct diagnosis.