Axillary radiotherapy (ART) is “preferred” over axillary lymph node dissection (ALND) in patients with sentinel node (SN)-positive early breast cancer, according to researchers.

Ten-year follow-up data from the AMAROS trial showed that locoregional control and survival outcomes were similar with ART and ALND. 

Researchers deemed ART the preferred treatment due to a lower likelihood of lymphedema. However, second cancers were more likely after ART than after ALND. 


Continue Reading

These findings were published in the Journal of Clinical Oncology.

The phase 3 trial (ClinicalTrials.gov Identifier: NCT00014612) included 1425 patients with cT1-2, node-negative breast cancer who had a positive SN biopsy. They were randomly assigned to ALND (n=744) or ART (n=681). Baseline characteristics were well balanced between the treatment arms. 

The median follow-up was 10 years. The 10-year cumulative axillary recurrence rate was 0.93% in the ALND arm and 1.82% in the ART arm (hazard ratio [HR], 1.71; 95% CI, 0.67-4.39). 

The 10-year disease-free survival rate was 75.0% in the ALND arm and 70.1% in the ART arm (HR, 1.19; 95% CI, 0.97-1.46; P =.11). The 10-year overall survival rate was 84.6% and 81.4%, respectively (HR, 1.17; 95% CI, 0.89-1.52; P =.26). 

In an updated 5-year analysis, the rate of lymphedema was 24.5% after ALND and 11.9% after ART (P <.001). The incidence of lymphedema reported at any point during follow-up was 44.2% after ALND and 28.6% after ART. 

In an exploratory analysis, the 10-year cumulative incidence of locoregional recurrence was 3.6% after ALND and 4.1% after ART (HR, 1.13; 95% CI, 0.65-1.20; P =.69).

The 10-year cumulative incidence of second primary cancer was 12.1% in the ART arm and 8.3% in the ALND arm (HR, 1.45; 95% CI, 1.03 to 2.04; P =.035).

“Although a slightly higher number of second primary cancers were observed after ART, the 10-year results of the AMAROS trial confirm excellent long-term local and regional control and low morbidity after ART for patients with early breast cancer and a positive SN biopsy,” the researchers concluded. “Considering less arm morbidity, ART is preferred over ALND for patients with SN-positive cT1-2 breast cancer.”

“[A]xillary dissection should be limited to patients with gross nodal disease,” Kathy D. Miller, MD, senior deputy editor of the journal, wrote in a comment. “For those with limited nodal disease, the real question is whether any axillary therapy is needed.” 

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Bartels SAL, Donker M, Poncet C, et al. Radiotherapy or surgery of the axilla after a positive sentinel node in breast cancer: 10-year results of the randomized controlled EORTC 10981-22023 AMAROS trial. J Clin Oncol. Published online November 16, 2022. doi:10.1200/JCO.22.01565