[Translational research and diagnostics for breast cancer]

In breast cancer, tumor biological markers are gaining impact and have become equal to traditional markers of pathology. Molecular expression profiling has led to new categories, which by receiving translation into immunohistochemical terms have entered routine pathology use. Besides the triple negative (basal) type, there are hormone receptor positive luminal A and B types and the HER2 type. The distinction between luminal A and B type is not yet clear cut and the proliferation marker Ki-67 as well as diverse RNA expression profiles are used for distinction in order to decide which patients might benefit from pure endocrine and which from combined chemo-endocrine therapy. Prospective studies are necessary to answer these questions. Study data are further awaited to clarify the heterogeneity of triple negative cases which include most of the BRCA1 associated cancers and to elucidate whether within the HER2 category, polysome or pseudopolysome cancer will respond to therapy.