Molecular medicine and personalized therapy for breast cancer patients

Abstract

Targeted therapy has been utilized for patients with breast cancer for over a century. Estrogen and progesterone receptors are well-established prognostic and predictive markers for hormonal therapy. The Ki67 proliferation percentage is used to determine the rate of cancer cell proliferation and HER2 to delineate the response to HER2 targeting therapy. In addition to the development of individual predictive and prognostic biomarkers, much emphasis has been placed upon the discovery of gene array patterns to elucidate prognostic and predictive factors. Routinely used in clinical practice to determine the need and benefit of adjuvant chemotherapy are the Oncotype DX and MammaPrint gene assays. A third multigene predictive marker, PAM50, has recently been introduced that analyzes a 50-gene signature. As more targeted therapies with matched biomarkers are being developed and approved for use in patients with metastatic disease, a personalization of therapy for early-stage breast cancer is likely to further evolve.