1999 Abstract: 2144 MORPHOLOGIC PARAMETERS AND BCL-2 AND BAX EXPRESSIOIN IN ADENOCARCINOMAS OF THE AMPULLA OF VATER AND PANCREAS - CORRELATION WITH PATIENT SURVIVAL
Abstracts
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PURPOSE: The purpose of this study was critically assess morphologic parameters and the expression of apoptotic markers in patients with adenocarcinomas of the ampulla of vater and pancreas and correlation these findings with patient survival. METHODS: Hematoxylin and eosin stained sections of Whipple resections for ampullary carcinoma (19 cases) and pancreatic carcinoma (18 cases) were histologically assessed for the following parameters: tumor size, histologic grade, surgical margins, extracellular and intracellular mucin, perineural invasion, and lymph node metastases. Tumor and 8 control sections of non-neoplastic pancreas were analyzed for immunohistochemical expression of the apoptosis-related proteins Bcl-2 and Bax. RESULTS: Tumor size (p=0.023), presence of perineural invasion (p=0.003), positive margins (p=0.07) and lymph node metastases (p=0.013) significantly correlate with decreased patient survival. Bivariate analysis reveals that the presence of perineural invasion and increased tumor size (p=0.003) most significantly correlate with decreased patient survival. 47% of infiltrating periampullary tumors and 28% of infiltrating pancreatic tumors express Bcl-2 while 94% of periampullary tumors and 92% of pancreatic tumors express Bax. There is no statistically significant association between Bcl-2 and Bax expression or intensity in either periampullary or pancreatic tumors and patient survival. Additionally, 2 patterns of Bcl-2 expression are noted. The first, in 47% of cases of pancreatic carcinoma, atypical and dysplastic noninvasive pancreatic duct epithelium express bcl-2 and in 32% of cases of ampullary carcinoma, adenomatous components express bcl-2. The second notable staining pattern is increased intensity of bcl-2 expression in ducts and acini in areas of chronic pancreatitis where present in 15/15 cases of pancreatic carcinoma. CONCLUSION: In the pathologic evaluation of Whipple resections of both pancreatic and ampullary carcinomas, perineural invasion and tumor size may be the 2 most important prognostic features. Neither the up regulation of the anti-apoptotc protein bcl-2 nor the pro-apoptotic protein Bax are related to patient prognosis in pancreatic or ampullary carcinomas. Bcl-2 may play a role in the early stage of carcinogenesis from progression of glandular or ductal epithelial atypia to infiltrating tumor. The up regulation of bcl-2 in areas of chronic pancreatitis suggests a possible relationship of the chronic inflammatory process and pancreatic tumor pathogenesis. Copyright 1996 - 1999, SSAT, Inc. |