Cytoplasmic-only Expression of Maspin Predicts Unfavorable Prognosis in Patients With Pancreatic Ductal Adenocarcinoma.

Background/aim Maspin is a tumor-suppressor protein expressed in >90% of pancreatic ductal adenocarcinoma (PDAC) cases. We aimed to assess the prognostic value of subcellular localization of maspin. Patients and methods Ninety-two resected PDAC specimens were immunohistochemically analyzed. Cytoplasmic-only expression observed in >10% of the tumor was defined as maspin-positive. Results The maspin-positive status (21.7%) was inversely correlated with well-differentiated histological type and indicated a shorter recurrence-free survival (RFS) and overall survival (OS). Cox's multivariate analysis showed that maspin-positive status was an independent factor for shorter RFS and OS. Maspin was localized to cytoplasm in AsPC-1 cells, but to both nucleus and cytoplasm in BxPC-3 cells. In AsPC-1 cells, cell invasion was significantly reduced in response to maspin suppression via transfection with siRNA targeting maspin, whereas no reduction was observed in BxPC-3 cells. Conclusion Cytoplasmic-only expression of maspin could be an independent unfavorable prognostic indicator for patients with PDAC.