Estrogen Receptor-Positive Breast Cancer: Traditional Prognostics, Molecular Pathology: A New Breast Cancer Taxonomy and 21st Century Personalized Prognostic and Predictive Assays

Abstract

Personalized Medicine, by the utilization of powerful gene expression technologies, is rapidly revolutionizing the clinical management of treatment decisions in patients with breast cancer. In addition to powerful traditional clinicopathologic metrics the new technologies offer the personalized assessment of individual patient tumor samples. By accurately quantitating gene expression and integrating these precise measurements into powerful biostatistical models, the risk of distant recurrence and the potential benefit of chemotherapy may be assessed for individual patients and their health-care providers. This personalized medical information allows for actionable, individualized treatment decisions. In addition to a detailed review of the traditional clinicopathologic metrics, this chapter will review current molecular assessment technologies as well as review landmark trials that use these tools in a prespecified manner in clinical validation trials and that demonstrate their clinical utility in the management of individual patient treatment decisions.