Notch 1 tumor expression is lacking in highly proliferative pancreatic neuroendocrine tumors

摘要

To date, very little is known about the development of benign organic hyperinsulinism and its meta-static potential. Typical morphologic, biochemical, or genetic differentiations for benign or malign tumor course of insulinomas do not exist. As signaling pathways may affect pancreatic cancer development and the maintenance of the neoplastic phenotype, the purpose of this study was to examine the role of Notchl expression in organic hyperinsulinism. We examined 32 well-differentiated pancreatic endocrine tumors (wd PET); 11 wd PET of unknown behavior (wd PET ub); and 15 wd pancreatic endocrine cancer (wd PEC) for Notchl expression by immunohistochemistry. Demographic data, clinical data, and follow-up of all patients were analyzed. Islets of the Langerhans show the strongest Notchl staining in nearly 90 . Positive Notchl staining was absent in the acinar of the pancreas. In patients with a wd PET more than every second tumor (56.3 /n = 18/32) demonstrated a negative Notchl staining. The other 14 patients were positive for Notchl. Tumors of unknown behavior (wd PET ub) and malignant insulinomas had no signs of Notch expression in contrast to benign insulinomas. Considering the clinical and histomorphological tumor behavior, no correlation between Notchl expression and clinical data was found. The missing Notch expression in the malignant tumor course might be used as a potential predictive marker, but further studies are needed to investigate the underlying molecular mechanism.