EXPRESSION OF P53 PROTEIN IN PRECURSOR LESIONS AND ADENOCARCINOMA OF HUMAN PANCREAS

To evaluate the incidence and stage at which p53 alterations occur in human pancreatic carcinogenesis, we examined primary and metastatic ca rcinomas, carcinoma in situ, and hyperplastic lesions with and without atypia for p53 protein overexpression by immunohistochemical procedur e. Overexpression of p53 was observed in 40% (10/25) of primary tumors , 29% (2/7) of metastatic tumors, 36% (5/14) of carcinoma in situ, and 35% (6/17) of hyperplastic lesions. These results suggest that p53 pr otein overexpression is not only a common genetic alteration but also occurs very early the development of these tumors. It is suggested tha t p53 overexpression can be used as a marker to identify precursor les ions that have increased potential to develop into malignant tumors.