Expression of p73 and p63 proteins in pancreatic adenocarcinoma: p73 overexpression is inversely correlated with biological aggressiveness.

The significance of p53, a prominent tumor suppressor gene, and its product in various neoplasms including pancreatic adenocarcinoma has been established. We investigated the expression of two types of homologue of p53, p73 and p63, in pancreatic adenocarcinoma by means of immunohistochemistry. Overexpression of p73 was observed in 45.6% of the cases and this phenomenon was more frequently seen in cystic adenocarcinomas than in ductal carcinomas. Furthermore, p73 overexpression was inversely linked to lymph node metastasis, tumor size, and Ki-67 labeling index. On the other hand, p63 overexpression was observed in 68.2% of the cases, but was not related to any clinicopathological features. No correlation was established between the expression of these proteins and aberrant p53 expression. These results suggest that decreased expression of p73 protein and over-expression of p63 protein may play a role in the development of pancreatic adenocarcinoma.