Clinical factors predictive of malignant and premalignant cystic neoplasms of the pancreas: a single institution experience

Background: As cystic neoplasms of the pancreas are discovered with advanced imaging techniques, pancreatic surgeons often struggle with identifying who is at risk of having or developing pancreatic cancer. We sought to review our experience with the surgical management of cystic neoplasms of the pancreas to determine pre-operative clinical indicators of malignancy or premalignant (i.e. mucinous) lesions. Methods: Between 1996 and 2007, 114 consecutive patients with cystic neoplasms of the pancreas underwent a pancreatectomy. Invasive adenocarcinoma was identified in 35 whereas 79 had benign lesions. Mucinous lesions were considered premalignant and consisted of 29 intraductal papillary mucinous neoplasms (IPMN) and 17 mucinous cystic neoplasms (MCN). The remaining 33 benign lesions were serous microcystic adenomas. Descriptive statistics were calculated and multivariate logistic regression was performed. Receiver-operating characteristic (ROC) curves were constructed for continuous variables and the area under the curves compared. Likelihood ratios were calculated from the combinations of predictors. Results: Patients with pancreatic cancer arising from a cystic neoplasm were older than those with benign cysts. Mucinous lesions with or without associated cancer were more likely to be symptomatic and present with elevated serum carbohydrate antigen (CA) 19-9 levels. Cancers more commonly presented in the head of the pancreas and were associated with longer hospitalizations after resection. Using multivariate logistic regression, size and elevated CA19-9 were predictors of malignancy whereas male gender and size were predictors of mucinous lesions with or without malignancy. Size, however, was not an accurate test to determine premalignant or malignant lesions using area under the ROC curve analysis whereas CA19-9 performed the best regardless of gender or lesion location. Conclusions: Based upon our single institution experience with resection of cystic neoplasms of the pancreas, we advocate an aggressive surgical approach to any patient with a cystic neoplasm of the pancreas and associated elevated CA19-9.