Reply to Madhu et al.

We thank Dr. Madhu and colleagues for their interest in our study [1] and their observations. We agree that there are important differences between postendoscopic ultrasound pancreatic cancer (PEPC) and both post-endoscopy upper GI cancer (PEUGIC) and post-colonoscopy colorectal cancer (PCCRC). Indeed, we were careful not to imply that they were directly analogous in our paper [1]. Endoscopic ultrasound (EUS) is performed in individuals with varying levels of pretest suspicion of cancer. This ranges from: those with obstructive jaundice and a clearly defined mass on prior imaging; to those with an isolated abnormality, such as a dilated pancreatic duct with no mass; through to individuals being investigated for apparently benign disease, such as pancreatitis, with no prior imaging suggestive of pancreatic cancer. The pretest probability of malignancy is usually much higher for EUS than is commonly the case for endoscopy and colonoscopy. However, while this does make the definition, interpretation, and analysis of PEPC more complex, it does not negate the importance of such efforts. We agree with Dr. Madhu and colleagues that PEPCs are not always due to a failure of EUS. It is however important to recognize that PEUGIC and PCCRC are also not always due to a failure of endoscopy and colonoscopy, as Dr. Madhu and colleagues imply, but commonly relate to decisionmaking following endoscopy and colonoscopy [2]. We acknowledge the difficulties raised by Dr. Madhu and colleagues regarding the timeframe for the PEPC definition. Further work is required to refine the timeframe we have used. The timeframe in our study does however provide a starting point for root-cause analysis of a large cohort of patients (with full access to clinical case records) with a final diagnosis of pancreatic cancer, who underwent EUS within 0–18 months, to not only define the true rate of PEPC but also to identify the appropriate time interval for its definition and to devise a PEPCspecific classification system. We thank Dr. Madhu and colleagues for their interest in our work and we value their robust critique of our study. This is an important area of research and ultimately future patients will benefit from critical examination of the times when our endoscopic procedures have apparently failed to diagnose cancer.