More Guidelines, Uniformity in Radiation Therapy Needed Following Chemotherapy, Surgery in Breast Cancer
Wide variability exists in radiation treatment decisions following neoadjuvant chemotherapy and surgery for breast cancer, according to a review of the American College of Surgeons Oncology Group (ACOSOG) Z1071 trial. These findings were published by Haffty et al in the International Journal of Radiation Oncology • Biology • Physics.
A multicenter phase II prospective trial, ACOSOG Z1071 evaluated the false-negative rate of sentinel lymph node surgery after neoadjuvant chemotherapy in 701 breast cancer patients with initial node-positive disease who met all eligibility requirements and underwent sentinel lymph node surgery followed by completion axillary lymph node dissection. A total of 685 patients enrolled in Z1071 were eligible for the current analysis, which sought to evaluate the variability of practice patterns following neoadjuvant chemotherapy.
Study authors focused primarily on surgical approaches, use of reconstruction after mastectomy, and use of postmastectomy, as well as regional nodal irradiation, nodal status, and response to neoadjuvant chemotherapy.
Variability in Treatment
After receiving chemotherapy, 401 (58.5%) patients remained node-positive, while 284 (41.5%) changed to node-negative. Of 401 node-positive patients, mastectomy was performed in 148 (36.9%), mastectomy with immediate reconstruction in 107 (26.7%), and breast-conserving surgery in 146 patients (36.4%). In women undergoing reconstruction, bilateral mastectomy rates were higher than in those who did not have reconstruction (66.5% vs 32.2%, respectively, P < .0001).
Most patients received radiation therapy, regardless of the surgical treatment of the primary tumor following neoadjuvant chemotherapy. Postmastectomy radiation therapy was more frequently omitted after reconstruction than mastectomy (23.9% vs 12.1%, respectively, P = .002) and was omitted in 19 of 107 patients (17.8%) with residual node-positive disease in the reconstruction group.
The use of internal mammary radiation therapy was low, between 7.8% and 11.2%, and did not differ with surgical approaches. The rate for supraclavicular radiation therapy ranged from 46.6% to 52.2%, and this measure was omitted in 193 node-positive patients (47.3%).
In patients who converted to node-negative status following neoadjuvant chemotherapy and were treated with breast-conserving surgery and radiation, regional nodal radiation was employed in approximately half and omitted in half, reflecting the need for more guidance.
“Patient and physician treatment decisions have been impacted by the increasing use of neoadjuvant chemotherapy,” said Bruce G. Haffty, MD, Interim Director of the Rutgers Cancer Institute of New Jersey and Department Chair of Radiation Oncology, Rutgers Robert Wood Johnson Medical School.
“This study revealed wide variability in practice, particularly regarding administration of radiation therapy and field design following neoadjuvant chemotherapy and surgery for breast cancer. Discussion and collaboration among all of the members of a multidisciplinary team of medical oncologists, surgical oncologists, and radiation oncologists is important for optimal management,” Dr. Haffty said. “Patients should be made aware that there are various approaches to local-regional management of breast cancer after neoadjuvant systemic therapy.”
“The study also emphasizes the importance of the ongoing national clinical trials regarding local-regional management of breast cancer after neoadjuvant chemotherapy,” he concluded.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
