Adjuvant Radiotherapy in Early-Stage Breast Cancer: Evidence-Based Options

Patients with a diagnosis of early-stage breast cancer are offered the option of either mastectomy or breast-conserving therapy (BCT) secondary to multiple randomized trials demonstrating equivalent long-term outcomes. Traditionally, BCT has used standard whole-breast irradiation (SWBI) after breast-conserving surgery, although several alternatives have emerged during the past few decades.

This report reviews key studies supporting each radiation technique and its respective eligibility criteria to assist clinicians in deciding which adjuvant radiotherapy options are appropriate for their patients.

In the past, completion of SWBI required 5-7 weeks of daily treatments. During the past two decades, alternatives to SWBI have emerged including hypofractionated whole-breast irradiation (3-4 weeks), accelerated partial-breast irradiation (1-3 weeks), and endocrine therapy alone. Multiple randomized trials have established the equivalence of these alternative strategies to SWBI for appropriately selected patients. Additionally, the current guidelines for patient selection demonstrate a large amount of overlap in the selection criteria for each technique.

Clinicians must evaluate patient and pathologic criteria and engage in informed discussions with patients when determining which adjuvant radiation techniques are appropriate. Future strategies being explored include using tumor genetics to identify low-risk patients and switching from paradigms that omit radiotherapy to those that omit endocrine therapy.