Adjuvant Radiotherapy in Low-Risk Breast Cancer Patients: Review and Clinical Implications

Chirag Shah, MD, Vivek Verma, MD, Michelle Frances Barrord, BS, Frank Vicini, MD
Published: Sunday, Jun 21, 2015
Chirag Shah, MD

About the lead author:
Chirag Shah, MD
Department of Radiation Oncology
Summa Health System

The Reviewer’s Viewpoint

David E. Wazer, MD, FACRO, FACR, FASTRO
David E. Wazer, MD, FACRO, FACR, FASTRO
Department of
Radiation Oncology
Tufts University
School of Medicine
Alpert Medical School
of Brown University

Why is this article contemporary?
Contemporary risk-adapted local therapy for early breast cancer is a complex and evolving paradigm. Shah et al do an excellent job in summarizing the multitude of evidence-based approaches related to risk stratification, treatment options, and results. By also placing these in the context of real-world case examples, clinicians can gain valuable insight into the appropriate application of these multifaceted clinical trial data to manage the individual patient. This review highlights the enormous progress that has been achieved in recent years toward providing women with local therapy options that are safe, effective, convenient, and cost efficient.

Abstract

Breast conserving therapy (BCT) offers women the ability to preserve their breast without sacrificing local control or survival. Since its inception, a key component of BCT has been the delivery of adjuvant radiotherapy following breast-conserving surgery (BCS). However, a growing interest remains in determining if there exists a subset of women with low-risk features for whom adjuvant radiotherapy may be omitted following BCS. To date, the data are consistent in demonstrating that adjuvant radiotherapy reduces the rate of local recurrences in all risk groups. In lower-risk groups, modern trials have failed to demonstrate a survival advantage from the local control benefit derived from radiotherapy. Currently, studies are being performed to identify low-risk patients based on tumor genetics, nomograms, and other techniques. In the interim, clinicians now have alternative techniques including hypofractionated whole breast irradiation as well as accelerated partial breast irradiation which allows for a reduction in treatment duration (and possibly treatment volume) while still maintaining local control.


Introduction

Over the past several decades, breast-conserving therapy (BCT) has emerged as the standard of care in the management of early-stage breast cancer. With greater than twenty-five years of follow-up, multiple randomized trials have demonstrated equivalence in outcomes between mastectomy and BCT, with BCT being shown to improve the quality of life of breast cancer survivors compared with mastectomy.1-4 A key component in the BCT arms of the randomized trials was standard fractionation whole-breast irradiation (WBI) delivered over 5 to 6 weeks. In the decades since the initial randomized trials, adjuvant radiation therapy (RT) has continued to be a key component of the BCT technique to optimize local control. While RT has been shown to enhance local control following breast-conserving surgery (BCS), concerns exist, including acute/chronic toxicities associated with treatment, the duration of treatment, and the potential for overtreatment.5,6 A key question being considered is the role of RT in patients who will not manifest large local control benefits with adjuvant RT compared with BCS with or without endocrine therapy. Multiple attempts have been made to omit RT following BCS, with mixed results. In spite of the lack of clarity, clinicians are facing pressure to tailor RT recommendations based on patient (age, performance status), pathologic (tumor size, margin status, grade, hormone receptor status, lymph node status), and systemic treatment (tamoxifen/aromatase inhibitor utilization) characteristics and to identify low-risk patients for whom RT may not be required. Therefore, the purpose of this clinical review is to evaluate the role of RT in low-risk patients (based on patient and pathologic features) following BCS and to provide common scenarios and recommendations based on current data and guidelines.

Discussion


View Conference Coverage
Online CME Activities
TitleExpiration DateCME Credits
Community Practice Connections™: 16th Annual International Congress on the Future of Breast Cancer®Sep 29, 20182.0
School of Breast Oncology®: Mid-Year Video Update OnlineSep 30, 20182.0
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