Absence of a Dilated Duct Predicts Benign Disease in Suspected Pancreas Cancer: A Simple Clinical Rule

Background Pancreatic cancer can be difficult to diagnose. Fine-needle aspiration (FNA) biopsies may be negative even when malignancy is present. Aims To identify endosonographic features predictive of malignancy that will separate patients into high- and low-risk groups, in whom a negative FNA effectively rules out malignancy. Methods Patients presenting for endoscopic ultrasound (EUS) evaluation for suspected pancreatic mass were prospectively enrolled. If a mass or abnormal lymph nodes were present, sampling via fine-needle aspiration (FNA) was performed. The characteristics of patients with cancer were compared to the characteristics of patients without cancer using Chi-square testing and t-tests. Results Seventy-three patients were enrolled. Thirty-three patients had cancer and 40 had benign disease. On multivariate analysis, only vascular or organ invasion and dilation of the pancreatic duct (PD) were significantly associated with cancer. PD dilation was examined as a stand-alone feature. The presence of a dilated PD placed patients into a group with a 65% prevalence of malignancy. In the non-dilated PD group, the prevalence of malignancy was only 17%, and in this group, the negative predictive value of FNA was 100%, compared to an NPV of 73% in the entire cohort. Conclusions The most significant negative predictive endosonographic finding in patients with suspected pancreatic cancer is a non-dilated PD. If a patient with suspected pancreatic cancer does not have a dilated PD and the FNA is negative for malignancy, the likelihood of cancer is low.