Current Status of Prognostic Profiling in Breast Cancer

Abstract

Abstract Learning Objectives After completing this course, the reader will be able to: Assess emerging data on the use of genetic groupings of breast cancer as predictive factors, and examine the efficacy of different therapies aimed at optimizing outcomes of patients within these groups.Examine the clinical value of molecular diagnostic tests being developed to classify breast tumors, and discuss the challenges involved in validating and interpreting the results of these tests.Outline the potential uses of identifying and/or targeting breast cancer stem cells.Discuss the possible effect of genetic classification of breast tumors on the design of future clinical trials. CME Access and take the CME test online and receive 1 AMA PRA Category 1 Credit™ at CME.TheOncologist.com Breast cancer is a clinically heterogeneous disease that can affect individuals with seemingly identical clinicopathologic parameters differently. This clinical heterogeneity is driven to a large extent by abnormal gene expression within tumors. Investigators now have the ability to identify the gene-expression fingerprint of an individual's tumor. This information may be used to rationally design therapeutic targets in the future, and also to predict the clinical course of an individual's disease, including response to a specific treatment. Genetic profiles of tumors are now being correlated with clinical outcome, and several prognostic and predictive indicators have emerged based on this research. There are at least four commercially available predictive or prognostic tests, and several more are looming on the horizon. The data gathered from these tests augment standard diagnostic and prognostic information obtained from traditional clinical pathological variables. The advent of gene-profiling technologies started to change the conduct of clinical trials. In the not too distant future, prospective tissue collection for molecular analysis may become routine in order to stratify patients for treatment arms and to optimize treatment strategies based on molecular features of the cancer. Coordinated efforts among oncologists, pathologists, surgeons, laboratory scientists, statisticians, and regulators will be essential in the quest to incorporate genetic profiling and molecular hypotheses into clinical trial planning and conduct.