The Landmark Series: Adjuvant Radiation Therapy for Breast Cancer

Radiation therapy represents a cornerstone of breast cancer treatment both for patients undergoing breast conservation and for those receiving mastectomy. Trials evaluating breast-conserving therapy have established the benefit of adjuvant radiation therapy in terms of both local control and breast cancer mortality, whereas trials evaluating post-mastectomy radiation therapy have demonstrated improved survival for appropriately selected patients. More recent trials have confirmed that axillary node dissection can be omitted for patients who have positive sentinel nodes with no impairment at locoregional recurrence and improved outcomes. Additionally, new studies have validated the finding that the addition of regional nodal irradiation to patients with limited nodal disease provides improved outcomes. With a growing focus on treatment de-intensification, studies evaluating partial-breast irradiation with brachytherapy and external beam have demonstrated outcomes comparable with those of whole-breast irradiation, whereas further study is needed regarding intraoperative radiation therapy. This study reviews these landmark studies to present a roadmap for how adjuvant radiation therapy is used to treat breast cancer patients at this time.