Postmastectomy Radiation Therapy: An ASTRO-ASCO-SSO Clinical Practice Guideline
Guidelines for post-mastectomy radiation include patients who received neoadjuvant therapy, with or without residual disease after treatment. A good topic to review.
Omitting Regional Nodal Irradiation after Response to Neoadjuvant Chemotherapy
Author(s): Eleftherios P. Mamounas, M.D.1; Hanna Bandos, Ph.D.2,3; Julia R. White, M.D.4; Thomas B. Julian, M.D.5; Atif J. Khan, M.D.6; Simona F. Shaitelman, M.D.7; Mylin A. Torres, M.D.8; Frank A. Vicini, M.D.9; Patricia A. Ganz, M.D.10,11; Susan A. McCloskey, M.D.12; Peter C. Lucas, M.D., Ph.D.13,14,15,16; Nilendu Gupta, Ph.D.17; X. Allen Li, Ph.D.18; Beryl McCormick, M.D.6; Benjamin Smith, M.D.7; Rahul D. Tendulkar, M.D.19,20; Vivek S. Kavadi, M.D.21; Koji Matsumoto, M.D.22; Samantha Andrews Seaward, M.D.23; William J. Irvin, Jr., M.D.24; Jolinta Y. Lin, M.D.8; Robert W. Mutter, M.D.25; Thierry M. Muanza, M.Sc.26; Jannifer Stromberg, M.D.27; Reshma Jagsi, M.D., Ph.D.8; Anna C. Weiss, M.D.28; Walter J. Curran, Jr., M.D.29; Norman Wolmark, M.D.14,15,30;
Source: N Engl J Med 2025;392:2113-2124
Dr. Maen Hussein's Thoughts
No need for radiation if neoadjuvant therapy led to a complete response in the lymph nodes.
BACKGROUND
The benefit of regional nodal irradiation in the treatment of breast cancer is well established for patients with pathologically positive axillary nodes, but whether it is also beneficial for patients whose nodes become pathologically tumor free (ypN0) after neoadjuvant chemotherapy remains unclear.
METHODS
We evaluated whether regional nodal irradiation improves outcomes in patients with biopsy-proven, node-positive breast cancer who reach ypN0 status after neoadjuvant chemotherapy. Patients with breast cancer with a clinical stage of T1 to T3 (tumor size, ≤2 cm to >5 cm), N1, and M0 (indicating spread to movable, ipsilateral level I and II axillary lymph nodes but no distant metastasis) who had ypN0 status after neoadjuvant chemotherapy were randomly assigned to receive regional nodal irradiation or no regional nodal irradiation. The primary end point was the interval of freedom from invasive breast cancer recurrence or death from breast cancer (invasive breast cancer recurrence—free interval). Secondary end points included the locoregional recurrence—free interval, the distant recurrence—free interval, disease-free survival, and overall survival. Safety was also assessed.
RESULTS
A total of 1641 patients were enrolled in the trial; 1556 were included in the primary-event analysis: 772 in the irradiation group and 784 in the no-irradiation group. After a median follow-up of 59.5 months, 109 primary end-point events (50 in the irradiation group and 59 in the no-irradiation group) had occurred. Regional nodal irradiation did not significantly increase the invasive breast cancer recurrence—free interval (hazard ratio, 0.88; 95% confidence interval, 0.60 to 1.28; P=0.51). Point estimates of survival free from the primary end-point events were 92.7% in the irradiation group and 91.8% in the no-irradiation group. Regional nodal irradiation did not increase the locoregional recurrence—free interval, the distant recurrence—free interval, disease-free survival, or overall survival. No deaths related to the protocol-specified therapy were reported, and no unexpected adverse events were observed. Grade 4 adverse events occurred in 0.5% of patients in the irradiation group and 0.1% of those in the no-irradiation group.
CONCLUSIONS
The addition of adjuvant regional nodal irradiation did not decrease the risk of invasive breast cancer recurrence or death from breast cancer in patients who had negative axillary nodes after neoadjuvant chemotherapy. (Funded by the National Institutes of Health; NSABP B-51—Radiation Therapy Oncology Group 1304 ClinicalTrials.gov number, NCT01872975.)
Author Affiliations
1AdventHealth Cancer Institute, Orlando, FL; 2NRG Oncology Statistical and Data Management Center, Pittsburgh; 3University of Pittsburgh School of Public Health, Department of Biostatistics and Health Data Science, Pittsburgh; 4University of Kansas Medical Center Comprehensive Cancer Center, Kansas City; 5Allegheny Health Network Cancer Institute, Pittsburgh; 6Memorial Sloan Kettering Cancer Center, New York; 7University of Texas M.D. Anderson Cancer Center, Houston; 8Winship Cancer Institute, Emory University School of Medicine, Atlanta; 9Michigan Healthcare Professionals, Pontiac; 10Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles; 11UCLA Fielding School of Public Health, Los Angeles; 12University of California, Los Angeles, Los Angeles; 13National Surgical Adjuvant Breast and Bowel Project Pathology Lab, Pittsburgh; 14University of Pittsburgh Medical Center Hillman Cancer Center, Pittsburgh; 15University of Pittsburgh School of Medicine, Pittsburgh; 16Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN; 17Ohio State University, James Cancer Hospital, Columbus; 18Medical College of Wisconsin, Milwaukee; 19Case Western Reserve University Case Comprehensive Cancer Center, Cleveland; 20Taussig Cancer Center, Cleveland Clinic, Cleveland; 21Texas Oncology, US Oncology Network, The Woodlands; 22Hyogo Cancer Center, Akashi, Hyogo, Japan; 23Kaiser Permanente National Cancer Institute Community Oncology Research Program, Vallejo, CA; 24Bon Secours Cancer Institute, Southeast Clinical Oncology Research Consortium, National Cancer Institute Community Oncology Research Program, Midlothian, VA; 25Mayo Clinic, Rochester, MN; 26McGill University, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montreal; 27Corewell Health, Oakland University Beaumont School of Medicine, Sterling Heights, MI; 28University of Rochester School of Medicine and Dentistry, Rochester, NY; 29Piedmont Oncology Institute, Atlanta; 30National Surgical Adjuvant Breast and Bowel Project Foundation, Pittsburgh;Related Articles
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