The impact of brush cytology from endoscopic retrograde cholangiopancreatography (ERCP) on patient management at a UK teaching hospital

INTRODUCTION Patients with suspected pancreaticobiliary cancers frequently undergo endoscopic retrograde cholangiopancreatography (ERCP) to obtain brush cytology for confirmatory diagnosis. The outcome of this often leads to the management of the patient and can avoid more invasive investigations. There is a wide range of sensitivities and specificities reported in the literature. AIMS To determine the accuracy of the brush cytology obtained at ERCP by performing a retrospective audit of all patients admitted to Guy's and St. Thomas' Hospital for ERCP during 2008-2013. Also, to evaluate the impact of cytology results on patient care following ERCP. METHOD Data were collected from 4 January 2008 to 27 December 2013. This involved analysing EndoSoft (the in-house software for endoscopic data entry), Pathnet (the pathology database) and Electronic Patient Records. RESULTS 162 patients underwent brush cytology during ERCP. 58 patients had positive cytology. With intention-to-treat analysis, sensitivity was 54.7%, specificity was 100.0% and negative predictive value was 53.9% with a positive predictive value of 100%. Patients with a positive brush cytology result required fewer investigations compared with patients with a negative cytology result. CONCLUSIONS Our results compare favourably with previous studies in the field. Brush cytology has been ignored in recent times due to perceived poor results and efficacy. Our audit shows that it can reduce the number of investigations required to reach a diagnosis of malignancy and so is a valuable tool in the diagnosis of pancreaticobiliary malignancies. However, better guidance on preparation of samples for cytology is needed to reduce the number of insufficient samples.