As reported in the Journal of Clinical Oncology by Bartels et al, 10-year outcomes from the phase III EORTC 10981-22023 AMAROS trial were similar with axillary lymph node dissection (ALND) vs axillary radiotherapy in patients with cT1–2, node-negative breast cancer and a positive sentinel node biopsy. However, ALND was associated with a significantly higher 5-year rate of lymphedema.
As stated by the investigators, “At 5 years, both modalities showed excellent and comparable axillary control, with significantly less morbidity after axillary radiotherapy.”
Study Details
In the open-label noninferiority trial, 4,806 patients underwent sentinel node biopsy; of these, 1,425 were sentinel node–positive and were randomly assigned to undergo ALND (n = 744) or axillary radiotherapy (n = 681). The current report provides findings in a preplanned 10-year analysis of axillary recurrence rate, overall survival, and disease-free survival, with an updated 5-year analysis of morbidity and quality of life.
Key Findings
On intention-to-treat analysis, 10-year cumulative incidence of axillary recurrence was 1.82% (95% confidence interval [CI] = 0.74%–2.94%; 11 events) in the axillary radiotherapy group vs 0.93% (95% CI = 0.18%–1.68%; 7 events) in the ALND group (hazard ratio [HR] = 1.71, 95% CI = 0.67–4.39).
At 10 years, overall survival was 81.4% (95% CI = 77.9%–84.4%) in the axillary radiotherapy group vs 84.6% (95% CI = 81.5%–87.1%) in the ALND group (HR =1.17, 95% CI = 0.89–1.52). At 10 years, disease-free survival was 70.1% (95% CI = 66.2%–73.6%) vs 75.0% (95% CI = 71.5%–78.2%; HR = 1.19, 95% CI = 0.97–1.46).
In an exploratory analysis, the cumulative incidence of locoregional recurrence at 10 years was 4.1% in the axillary radiotherapy group vs 3.6% in the ALND group (HR = 1.13, 95% CI = 0.65%–1.20%).
At 5 years, lymphedema had occurred in 24.5% of patients in the ALND group vs 11.9% of the axillary radiotherapy group (P < .001). Quality-of-life scales did not differ between groups through 5 years.
An exploratory analysis showed an 8.3% 10-year cumulative incidence of second primary cancers in the ALND group vs 12.1% in the axillary radiotherapy group (HR = 1.45, 95% CI = 1.03%–2.04%). A total of 21 of 75 events in the axillary radiotherapy group and 11 of 57 events in the ALND group were either contralateral breast cancer or ductal carcinoma in situ.
The investigators concluded, “This 10-year analysis confirms a low axillary recurrence rate after both axillary radiotherapy and ALND with no difference in overall survival, disease-free survival, and locoregional control. Considering less arm morbidity, axillary radiotherapy is preferred over ALND for patients with sentinel node–positive cT1-2 breast cancer.”
Sanne A.L. Bartels, MD, PhD, MSc, of the Department of Surgical Oncology, the Netherlands Cancer Institute, Amsterdam, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the EORTC Cancer Research Fund. For full disclosures of the study authors, visit ascopubs.org.
