Breast tumor evolution.

Abstract

Abstract Abstract #PD1-1 Breast tumors are heterogeneous and composed of a variety of cell types with distinct genetic, epigenetic, and phenotypic profiles. However, the molecular basis underlying this intra-tumoral heterogeneity has not been defined. Models that attempt to explain this include the malignant stem cell hypothesis and the genetic diversity combined with clonal selection models. Both of these ideas have been investigated for a long time both in human tumors and in various model systems, leading to the accumulation of numerous findings that are used to support one or the other. Although the two models share some similarities, they explain tumor progression, therapeutic resistance, and recurrence in fundamentally different ways. Increasing data suggest that the cancer stem cell phenotype may just be a consequence of genetic and epigenetic events that occur in tumor cells and that it may change as tumors evolve. Furthermore, there may be differences among tumor types regarding the applicability of the cancer stem cell and clonal evolution models. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr PD1-1.