- 10-year locoregional control and survival rates are similar with axillary lymph node radiotherapy (RT) vs axillary lymph node dissection (ALND) in patients with early breast cancer and a positive sentinel lymph node (SLN) biopsy, according to data from the phase 3 AMAROS trial.
Why this matters
- Axillary RT can be considered as an noninferior alternative to ALND in this population.
- Noninferiority trial of 1425 patients with early-stage, clinically node-negative breast cancer and positive SLN biopsy, randomly assigned to ALND (n=744) or axillary RT (n=681).
- Median tumor sizes were 17 (range, 13-22) mm and 18 (range, 13-23) mm, respectively.
- Funding: European Organization for Research and Treatment of Cancer Charitable Trust.
- No disclosures.
- At 10 years:
- Cumulative rate of axillary recurrence was similar for axillary RT and ALND (1.82% vs 0.93%; HR, 1.71; P=.365)
- DFS events were similar between groups (188 vs 174 events; HR, 1.19; P=.105).
- Distant metastases-free survival was similar between groups (78.2% vs 81.7%; P=.19), as was OS (81.4% vs 84.6%; P=.26).
- 10-year cumulative incidence rate of second primaries was higher with axillary RT (75 vs 57 cases [12.09% vs 8.33%]; HR, 1.45; P=.035), including a higher rate of contralateral breast cancer (21 vs 11 cases).
- Prior 5-year data demonstrated that axillary RT was associated with significantly less lymphedema vs ALND (29.4% vs 14.6%; P<.0001>
- Radiation field size exceeded today’s practice.
- Overall recurrence rate was lower than expected.