Oncology Learning NetworkLoco-Regional Irradiation for Patients with Biopsy-Proven Axillary Node Involvement Who Become Node-Negative After Neoadjuvant Chemotherapy

The study concluded that omitting adjuvant regional nodal irradiation (RNI) after surgery did not compromise clinical outcomes over a median follow-up of 59.5 months.

In this video, Eleftherios Mamounas, MD, Orlando Health Cancer Institute, Florida, discussed primary results from the NRG Oncology/NSABP B-51/RTOG 1304 study at the 2023 San Antonio Breast Cancer Symposium (SABCS) in December. In addition, recent advancements in breast cancer treatment suggest that certain patient groups may benefit from a revised approach to radiotherapy. Additional studies presented at the SABCS explored the efficacy and necessity of adjuvant radiotherapy in distinct patient populations, including those with low-risk ductal carcinoma in situ (DCIS), postmenopausal early-stage breast cancer, and patients who achieved axillary lymph node negativity post-neoadjuvant chemotherapy. These findings challenge traditional treatment protocols, offering new insights for patient-centric care.

Key Points:

• NRG Oncology/NSABP B-51/RTOG 1304 Trial: This study examined the effects of adjuvant regional nodal irradiation, including treatment of the chest wall after mastectomy and whole breast irradiation after breast-conserving surgery, on patients with biopsy-proven axillary node involvement who become node-negative after receiving neoadjuvant chemotherapy. The results indicated that this approach did not improve survival outcomes for these patients
• IDEA Trial: Conducted by Dr. Reshma Jagsi, this trial involved younger postmenopausal patients with stage 1 hormone receptor-positive breast cancer. It found that patients with a low risk of disease recurrence (scores 18 or lower on the Oncotype DX Breast Recurrence Score) could skip radiotherapy post-breast-conserving surgery without a significant risk of disease recurrence within five years​​.
• E4112 Trial: Led by Dr. Seema Khan, this study examined the utility of adjuvant radiotherapy in patients with low-risk DCIS. The trial employed the Oncotype DX Breast DCIS Score to stratify patients for adjuvant radiotherapy following breast-conserving surgery. Results showed that patients with low-risk DCIS could forgo radiotherapy without a higher risk of disease recurrence within five years​​.
• Patient Experience and Choice: The studies emphasized the importance of patient choice and experience in cancer treatment, recognizing the need for multiple treatment options and informed decision-making​​.
• Broader Implications: These findings have broader implications for treatment protocols, suggesting that some patients could benefit from less aggressive treatment approaches, thereby reducing the burden of side effects and logistical challenges associated with traditional radiotherapy​​.

“Our findings suggest that downstaging cancer-positive regional lymph nodes with neoadjuvant chemotherapy can allow some patients to skip adjuvant RNI without adversely affecting oncologic outcomes. Follow-up of patients for long-term outcomes continues.”
— Eleftherios “Terry” Mamounas, Chair of the NRG Oncology Breast Committee, a Professor at the University of Central Florida, and Medical Director of the Comprehensive Breast Program at the Orlando Health Cancer Institute

More on Breast Cancer