Pancreatic-polypeptide in the human pancreas: expression and quantitative variation during development and in ductal adenocarcinoma.

Abstract

AIM: To determine the immunoreactivity of pancreatic-polypeptide (PP) during the development of the human fetal pancreas and ductal pancreatic adenocarcinoma, given that, PP positive cells were demonstrated either into its embryonic anlage or into pancreatic cancer. METHODS: Tissue sections from 15 pancreatic fetal specimens, and equal number of ductal adenocarcinoma specimens, were assessed. RESULTS: The density of positive cells in the primitive exocrine ductal epithelium and endocrine epithelium was significantly higher than the relevant density in the neoplastic pancreatic tissue of mixed (ductal - endocrine) and pure ductal type (p1 = 0.001, p2 < 0.0005, p3 = 0.046 and p4 < 0.0005 respectively). The above values were estimated during the 10th to 12th week. There was no significant difference in the density of positive cells in the mantle zone of the islets from the 13th to the 24th week, and the neoplastic tissue of mixed (p5 = 0.11) and pure ductal type (p6 = 0.23). CONCLUSION: The immunostaining for PP identifies a subgroup of pancreatic ductal adenocarcinomas with a neuroendocrine component, initially considered as pure ductal tumors, and mixed ductal and neuroendocrine tumors. This pattern of expression in neoplasms recapitulates the normal pattern during the embryonal development of the organ, raising the question of therapeutic efficacy of PP and analogues as potential adjuvant treatment of pancreatic cancer.