Purpose of reviewBreast cancer heterogeneity constitutes a significant investigational and therapeutic challenge. Here we review recent findings on breast cancer heterogeneity, focusing on its extent across the distinct molecular subtypes, the degree of spatial and temporal intra-tumor heterogeneity, and possible approaches to dissect and counteract it.Recent findingsRecent massively parallel sequencing studies have solidified the notion that estrogen receptor (ER)-positive and ER-negative breast cancers have divergent genetic landscapes. Numerous studies have addressed the origins of heterogeneity and the challenges it poses for patient management; however, its dynamic evolution in the light of novel targeted therapies is yet to be fully understood.SummaryTumor heterogeneity poses diagnostic and therapeutic challenges. Implementation of novel methodologies, such as single cell sequencing and analysis of cell-free DNA, might afford us the means to comprehend intra-tumor heterogeneity with greater precision, and to overcome the diagnostic and therapeutic challenges posed by it. |
