No abstract

Addition of FISH and mutation analyses to cytology analysis significantly increased the level of sensitivity with which we detected malignancy in biliary strictures, with 100% specificity. These techniques can be performed using standard brush samples collected during endoscopic retrograde cholangiopancreatography, with mutations detected in free DNA in supernatant fluid of samples. The tests are complementary and therefore should be used sequentially in the diagnostic evaluation of biliary strictures.

The high specificity of FISH polysomy/9p21 suggests that a positive result is sufficient for diagnosing malignancy in indeterminate strictures. The significantly higher sensitivity of FISH polysomy/9p21 compared to cytology supports the use of FISH in all non-diagnostic cases. Although both EUS-FNA and CBx were complimentary, our results suggest that distal strictures should be evaluated by EUS initially. Proximal strictures may be evaluated by FISH first and then by CBx if inconclusive.

Summary Background Because most pancreatic intraductal papillary mucinous neoplasms (IPMNs) will never become malignant, currently advocated long‐term surveillance is low‐yield for most individuals. Aim To develop a score chart identifying IPMNs at lowest risk of developing worrisome features or high‐risk stigmata. Methods We combined prospectively maintained pancreatic cyst surveillance databases of three academic institutions. Patients were included if they had a presumed side‐branch IPMN, without worrisome features or high‐risk stigmata at baseline (as defined by the 2012 international Fukuoka guidelines), and were followed ≥ 12 months. The endpoint was development of one or more worrisome features or high‐risk stigmata during follow‐up. We created a multivariable prediction model using Cox‐proportional logistic regression analysis and performed an internal‐external validation. Results 875 patients were included. After a mean follow‐up of 50 months (range 12‐157), 116 (13%) patients developed worrisome features or high‐risk stigmata. The final model included cyst size (HR 1.12, 95% CI 1.09‐1.15), cyst multifocality (HR 1.49, 95% CI 1.01‐2.18), ever having smoked (HR 1.40, 95% CI 0.95‐2.04), history of acute pancreatitis (HR 2.07, 95% CI 1.21‐3.55), and history of extrapancreatic malignancy (HR 1.34, 95% CI 0.91‐1.97). After validation, the model had good discriminative ability (C‐statistic 0.72 in the Mayo cohort, 0.71 in the Columbia cohort, 0.64 in the Erasmus cohort). Conclusion In presumed side branch IPMNs without worrisome features or high‐risk stigmata at baseline, the Dutch‐American Risk stratification Tool (DART‐1) successfully identifies pancreatic lesions at low risk of developing worrisome features or high‐risk stigmata.

Our study demonstrates that low-risk suspected IPMNs carry a small but clinically relevant risk of disease progression and provides data on baseline characteristics that may help in risk stratification.