Using molecular profiles to tailor treatment in breast cancer: are they ready for prime time?

In this article, recent developments with molecular profiling in breast cancer and future directions will be highlighted. Gene-expression profiling revealed four major biologic subtypes that reflect intertumoral heterogeneity of breast cancer and have led to the development of prognostic tools to facilitate adequate treatment in early breast cancer. A number of commercially available prognostic tests have been introduced for implementation in clinical routine. Also, predictive tools and approaches to characterize molecular portraits of metastatic breast cancer in order to overcome treatment resistance have been investigated. Efforts to identify the quantity and quality of clonal selection and genomic variability through modern genomic profiling led successfully to new insights into targeted treatment with more effective drugs and the promise to overcome resistance. Multigene approaches and novel microarray platforms such as the next-generation sequencing technology are feasible in clinical practice in order to assess the prognosis more precisely and to identify new molecular targets for developing more effective drugs in the near future.