Title: Tu1233 The Clinical Outcome of Incidental Pancreatic Cystic Neoplasms in Elderly Patients
Abstract: Introduction:The indications for resection of the branch duct type IPMN have been controversial, because branch duct type IPMN generally has a low risk of malignancy, although surgical resection is required for all main duct type IPMN, because of its high malignant potential.Therefore, in this study, we identified predictors of malignancy to determine indications for surgery for the patients with branch duct type IPMN.Methods: We retrospectively analyzed the clinicopathological factors of 162 patients who underwent resection for branch duct type IPMN at Wakayama Medical University Hospital from July 1999 to October 2012, to identify predictors of the malignant behavior of this neoplasm.For the purpose of the analyses, we classified IPMN with adenoma as a benign IPMN group, whereas noninvasive and invasive IPMC were classified as a malignant IPMN group.The ROC curves were used to determine the cutoff levels for the tumor size, main pancreatic duct (MPD) size, mural nodule size, and CEA level in the pancreatic juice to differentiate between benign and malignant IPMN in the patients with the branch duct type IPMN.Results: Of 162 patients, 60 patients (37%) had adenoma, 53 patients (33%) had noninvasive IPMC, and 49 patients (30%) had invasive IPMC.The areas under curve for the tumor size, MPD size, mural nodule size, and CEA level in the pancreatic juice were 0.612, 0.711, 0.819, and 0.920, respectively, and the determined cutoff levels for the differentiation between benign and malignant IPMNs were 30 mm, 5 mm, 5 mm and 30 ng/ml, respectively.We found 6 significant predictors for malignancy in the branch duct type IPMN in a univariate analysis; jaundice (P,0.01),MPD size .5mm(P,0.01),mural nodule size .5mm(P,0.01),elevated serum CA19-9 level (P,0.01),positive cytology in the pancreatic juice (P=0.02), and CEA level in the pancreatic juice .30ng/ml(P,0.01).In a multivariate analysis, a mural nodule size .5mm(P,0.01,odds ratio (95% CI); 12.9 (2.3-70)) and a CEA level in the pancreatic juice .30ng/ml(P,0.01,odds ratio (95% CI); 299 (18-5067)) were independent factors associated with malignancy.When the combination of a mural nodule size .5mmand a CEA level in the pancreatic juice .30ng/ml is used, the positive predictive value was 100% (45/45), and the negative predictive value was 96.6% (28/29).Conclusion: We identified two useful predictive factors for malignancy in branch duct type IPMN; a mural nodule size .5mmand a CEA level in the pancreatic juice obtained by preoperative ERP .30ng/ml.