Expression of Ki-67,p53,and K-ras in chronic pancreatitis and pancreatic ductal adenocarcinoma

摘要

AIM: To examine surgical specimens of pancreas with either chronic pancreatitis or pancreatic cancer in order to study whether ductal hyperplasia and dysplasia in pancreas represent precursor lesions for pancreatic cancer.METHODS: We examined expression of Ki-67, CEA,p53, and K-ras, in the surgical specimens of pancreas with adenocarcinomas (n = 11) and chronic pancreatitis (n = 12). Cellular proliferation was assessed by Ki-67proliferation index using the proliferation marker Ki-67.In specimens with pancreas cancer, we divided pancreas epithelium into normal (n=7), ductal hyperplasia (n=3), dysplasia (n=4), and cancerous lesion (n=11) after hematoxylin and eosin staining, Ki-67, and CEA immunohistochemical staining. In cases with chronic pancreatitis, the specimen was pathologically examined as in cases with pancreas cancer, and they were also determined as normal (n=10), ductal hyperplasia (n=4), or dysplasia (n= 5). p53 and K-ras expression were also studied by immunohistochemical staining.RESULTS: In pancreatic cancer, the Ki-67 index was 3.73±3.58 in normal site, 6.62±4.39 in ductalhyperplasia, 13.47±4.02 in dysplasia and 37.03±10.05in cancer tissue, respectively. Overall, p53 was positive in normal ducts, ductal hyperplasia, dysplasia, and carcinoma cells in 0 of 14 (0%), 0 of 7 (0%), 7 of 9 (78%),and 10 of 11 (91%), respectively, and K-ras was positive in 0 of 8 (0%), 1 of 3 (33%), 4 of 6 (67%), 4 of 5 (80%),respectively.CONCLUSION: Our results favorably support the hypothesis that ductal hyperplasia and dysplasia of the pancreas might be precursor lesions for pancreas cancer.Further evaluation of oncogenes by the molecular study is needed.