Background: The two-gene expression ratio HOXB13:IL17BR has been proposed to predict

Background: Today, no objective criteria exist to differentiate between individual primary tumors and intra-or intermammary dissemination respectively, in patients diagnosed with two or more synchronous breast cancers. To elucidate whether these tumors most likely arise through clonal expansion, or whether they represent individual primary tumors is of tumor biological interest and may have clinical implications. In this respect, high resolution genomic profiling may provide a more reliable approach than conventional histopathological and tumor biological factors.