RESUMO
Validated prognostic and predictive factors currently play an important role in treatment planning for patients with early-stage breast cancer. The role of personalized medicine has led to the search for markers that can be applied to individual patients to optimize treatment regimens. In addition to traditional clinicopathologic measures, scores and gene tests have been developed to independently predict risk of patients in the neoadjuvant and adjuvant settings. The discovery of these markers provides the opportunity to identify patients at such low risk of recurrence that toxic therapy side effects are not justified. Selection and management of patients with early-stage, hormone receptor-positive breast cancer who are appropriately treated with endocrine therapy alone after receiving locoregional therapy but do not necessarily require adjuvant chemotherapy is currently problematic. This article reviews the current state-of-theart biomarker assessment methods and discusses the potential role for the prediction of chemotherapy benefit focusing on endocrine sensitive disease.