A Nomogram for Predicting the Probability of Carcinoma in Patients with Intraductal Papillary-Mucinous Neoplasm

Background The objective of the present study was to use clinical and laboratory data to develop a model for predicting the presence of carcinoma in patients with intraductal papillary mucinous neoplasm (IPMN). Methods Data were collected on 81 patients with IPMN who underwent a pancreatic resection between 1989 and 2008 at Aichi Cancer Center Hospital. Variables analyzed included age, gender, laboratory findings (serum amylase, carcinoembryonic antigen, and carbohydrate antigen 19-9 level), pancreatic juice cytology grade, and imaging studies. Factors associated with the presence of carcinoma were evaluated by univariate and multivariate logistic regression analysis. Results Among the 81 patients with IPMN, 34 (42%) had malignant tumors (noninvasive carcinoma in 22 and invasive carcinoma in 12), and 47 (58%) had adenoma. On multivariate analysis, existing carcinoma was associated with female gender, main pancreatic duct IPMN, nodule size, and pancreatic juice cytology grade. Based on these variables, a predictive nomogram was developed. The area under the receiver operating characteristic curve (AUC) for the model was 0.903. The sensitivity and specificity of the model were 97.1 and 68.1%, respectively, in the validation study, for which the predictive probability of >10% was used to indicate the presence of carcinoma. Conclusions The nomogram has high diagnostic predictability for carcinoma in patients with IPMN and for individual cancer probability. This instrument may help to identify patients who need a surgical procedure.