SENOMAC Reveals Omitting ALND Yields Non-Inferior Survival in Breast Cancer

The phase 3 SENOMAC trial (NCT02240472) demonstrated non-inferior survival outcomes for patients with breast cancer and macrometastases who omitted axillary lymph node dissection (ALND).¹ These results, presented at 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, demonstrated a 5-year overall survival (OS) rate of 93.4% (95% CI, 91.9%-94.9%) in the completion ALND group vs 94.4% (95% CI, 93.1%-95.7%) in the omission group (HR, 0.89; 95% CI, 0.67-1.17; P < .001). Of note, the 5-year breast cancer-specific survival rate was 97.2% vs 97.9%, respectively.

During the conference, CancerNetwork® spoke with Jana de Boniface, MD, adjunct professor in the Department of Medical Epidemiology and Biostatistics at the Karolinska Institute, regarding the findings and the implications for radiation and surgical oncologists.

Furthermore, 1 sentinel lymph node macrometastasis was noted in 84.6% of patients, and 10.2% had an additional one. An extranodal extension was observed in 34.3% of patients. Adjuvant radiotherapy to the regional nodes was also given to 87.9% of patients with completed ALND vs 89.7% who had omission. At 5 years, severe or very severe problems for arm physical function were observed in 12.6% of patients who underwent ALND vs 3.6% who did not (P <.001).

Transcript:

In the SENOMAC trial, we allowed sites to apply international guidelines or national guidelines to their patients, so adjuvant treatment was as per standard of care at that site, which means that a majority of patients had nodal radiotherapy. This is not a trial that can tell us that you can omit the actual lymph node dissection and the radiotherapy towards the lymph nodes. We had published, in 2024, the Radiotherapy Quality Assessment, where you find all the different volumes and such, and we’re very confident that the reported radiotherapy is exactly what has been given, so the quality of the reporting has been very good.²

References

1. de Boniface J, Filtenborg Tvedskov T, Rydén L, et al. Omission of completion axillary dissection in patients with breast cancer and sentinel lymph node macrometastases: overall survival and patient-reported arm morbidity from the randomized SENOMAC trial. J Clin Oncol. 2026;44(suppl 16):LBA503. Doi:10.1200/JCO.2026/4417_suppl.LBA503
2. Alkner S, Wieslander E, Lundstedt D, et al. Quality assessment of radiotherapy in the prospective randomized SENOMAC trial. Radiother Oncol. 2024;197:110372. doi:10.1016/j.radonc.2024.110372