DR-412 Breast cancer with APOBEC mutagenesis evolve during progression

APOBEC mutagenesis are more profoundly present in metastatic breast cancer, particularly in ER+/HER2- breast cancer. This suggests that APOBEC driven breast cancers are intrinsically more aggressive, and that APOBEC driven tumor cells have a higher metastatic capacity. However, to date this is only supported by indirect evidence. Therefore, we aim to provide direct support for the connection between APOBEC mutagenesis and clinical outcome. Furthermore, BCs with APOBEC mutagenesis may be more heterogeneous or genetically more unstable allowing them to evolve more rapidly which are potential biological aspects of APOBEC mutagenesis that need to be explored.

John Martens, Erasmus MC, the Netherlands