The comparison of IHC and FISH demonstrated an excellent correlation of high-level HER-2/neu overexpression (3+) with gene amplification; ie, FISH does not provide further information in these tumors. However, weakly positive IHC results (2+) obtained with the HercepTest share only a minor association with gene amplification.

Our data indicate that bcl-2 expression is characteristic of the early phase of colorectal carcinogenesis. Its physiologic function as an inhibitor of PCD is preserved in most colorectal carcinomas, whereas p53 is apparently not involved in the regulation of PCD in colorectal neoplasias. bcl-2 expression in colorectal carcinomas is associated with a better clinical course. This correlation became even more evident in the subgroups of patients with carcinomas that also had low PCD index or lacked p53 immunoreactivity.

No abstract

The endothelium is one of the largest cellular compartments of the human body and has a high proliferative potential. However , angiosarcomas are among the rarest malignancies. Despite this interesting contradiction , data on growth and angiogenesis control mechanisms of angiosarcomas are scarce. In this study of 19 angiosarcomas and 10 benign vascular control lesions we investigated the sequence and expression of the p53 tumor suppressor gene and the expression of the mdm-2 proto-oncogene , which is a negative regulator of p53 activity and of the vascular endothelial growth factor (VEGF) , whose expression, among other factors , is regulated by the p53/MDM-2 pathway. Ten sarcomas (53%) exibited clear nuclear p53 protein accumulation. Two of these cases revealed mutations in the sequence-specific DNA binding domain of the p53 gene. Thirteen angiosarcomas (68%) showed an increased amount of MDM-2 protein. Elevated expression of p53 and MDM-2 protein correlated with increased VEGF expression , which was found in nearly 80% of the angiosarcoma cases. Negative or clearly lower immunostaining was obtained in cases from the benign control collective.