Primary vascular tumors of bone are a heterogeneous group. Numerous terms have been introduced as well as different classification systems. However, so far none of them have been generally accepted... Show morePrimary vascular tumors of bone are a heterogeneous group. Numerous terms have been introduced as well as different classification systems. However, so far none of them have been generally accepted.Therefor, there is a need for more specific morphological, immunohistochemical and molecular tools to support the classification of different vascular tumors of bone. In this thesis, we attempt to delineate the high-grade malignant vascular tumors of bone based on histomorphological criteria, protein expression profile based on a large panel of oncogenes, tumor-suppressor genes and signaling molecules, and molecular data. Moreover, we compared our dataset with a small groups of angiosarcoma of soft tissue in order to see whether these are truly different tumors or whether they should be regarded as one entity with a different localization. Finally, we question whether the rare vascular tumor previously designated as "haemangiopericytoma of bone" is a true entity or should rather be regarded as a growth pattern. Show less
This thesis describes the search for new high-risk breast cancer susceptibility genes by linkage analysis. To date 20-25% of familial breast cancer is explained by mutations in the high-risk BRCA1... Show moreThis thesis describes the search for new high-risk breast cancer susceptibility genes by linkage analysis. To date 20-25% of familial breast cancer is explained by mutations in the high-risk BRCA1 and BRCA2 breast cancer susceptibility genes. For the remaining families the genetic etiology is unknown. It is still possible that other high-penetrant genes play a role. Although a polygenic model with multiple low-penetrant genes acting additive or multiplicative will probable explain most of the BRCA1/2 negative families. Linkage in an international set of 150 high-risk breast cancer families couldn__t identify high-risk genes. However when limiting the linkage analysis to Dutch families only, we identified 9q21-22 as a putative breast cancer susceptibility locus Show less
