Omitting Axillary Lymph Node Dissection: Safe for Patients with Breast Cancer Spread to One or Two Sentinel Lymph Nodes An interview with: Jana de Boniface MD PhD Department of Surgery, Capio St. Göra
Omitting Axillary Lymph Node Dissection: Safe for Patients with Breast Cancer Spread to One or Two Sentinel Lymph Nodes
An interview with:
Jana de Boniface MD PhD
Department of Surgery, Capio St. Göran’s Hospital, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
CHICAGO, USA—More women with breast cancer can avoid debilitating side effects including lymphedema by skipping axillary lymph node detection even if they have up to two involved lymph nodes. This is the finding of the …..
Study, reported at the 2026 Annual Meeting of the American Society of Clinical Oncology.
For the Audio Journal of Oncology, Peter Goodwin heard from first author, Jana de Boniface, MD, PhD, Clinical Professor at the Dept. of Medical Epidemiology and Biostatistics, Karolinska Institutet, and the Dept. of Surgery Breast Unit in Capio St. Göran’s Hospital, Stockholm, Sweden
AUDIO JOURNAL OF ONCOLOGY: Jana de Boniface, MD, PhD
IN:[GOODWIN]” I am at the ….
OUT: ……in Chicago. I’m Peter Goodwin 6:31 secs
ASCO Abstract #: LBA503
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.
Authors:
Jana de Boniface, Tove F. Tvedskov, Lisa Rydén, Robert Szulkin, Matilda Appelgren, Toralf Reimer, Thorsten Kühn, Michalis Kontos, Oreste D. Gentilini, Roger Olofsson Bagge, Malin Sund, Dan Lundstedt, Johan Ahlgren, Sara Alkner, Yvette Andersson, Birgitte V. Offersen, Leif Bergkvist, Jan Frisell, Peer Christiansen, SENOMAC Trialists’ Group
Organizations:
Department of Surgery, Capio St. Göran’s Hospital and Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark 4 Department of Breast Surgery, Gentofte Hospital, Copenhagen, Denmark, Department of Oncology and Surgery, Faculty of Medicine, Institute of Clinical Sciences, Lund University, Lund, Sweden and Skåne University Hospital Lund, Department of Gastroenterology and Surgery, Malmö, Sweden, Lund, Sweden, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden, Department of Obstetrics and Gynecology, University of Rostock, Rostock, Germany, Department of Gynecology and Obstetrics, University of Ulm; Breast Cancer Center, Die Filderklinik, Ulm; Filderstadt, Germany, Department of Surgery, University of Athens Laiko Hospital, Athens, Greece, Breast Unit, IRCCS San Raffaele Scientific Institute/ Università Vita-Salute San Raffaele, Milan, Italy, Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden, Department of Surgery, University of Helsinki and Helsinki University Hospital, Finland and Department of Diagnostics and Intervention/ Surgery, Umeå University, Sweden, Umeå, Sweden, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden and Department of Oncology at Sahlgrenska University Hospital, Gothenburg, Sweden, Göteborg, Sweden, Department of Oncology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden and Regional Cancer Centre of Mid-Sweden, Uppsala, Sweden, Department of Oncology, Faculty of Medicine, Institute of Clinical Sciences, Lund University, Lund, Sweden and Skåne University Hospital Lund, Department of Hematology, Oncology and Radiation Physics, Lund, Sweden, Department of Surgery, Vastmanland Hospital Vasteras, Vasteras, Sweden and Centre for Clinical Research, Uppsala University and Region Vastmanland, Vastmanland Hospital Vasteras, Västerås, Sweden, Department of Oncology, Aarhus University Hospital, Aarhus University, Aarhus, Denmark and Department of Experimental Clinical Oncology, Danish Center for Particle Therapy, Aarhus, Denmark, Aarhus, Denmark, Center for Clinical Research, Uppsala University, Västmanland Central Hospital, Västerås, Sweden, Karolinska Institutet, Stockholm, Sweden, Aarhus University Hospital, Aarhus, Denmark,
Background:
Axillary lymph node dissection (ALND) causes arm-related morbidity. The SENOMAC trial evaluates whether the omission of completion ALND in patients with 1-2 sentinel lymph node (SLN) macrometastases is oncologically safe. It differs from previous trials in size and the inclusion of larger tumors and patients receiving mastectomy.
Methods:
SENOMAC (NCT02240472) is an international non-inferiority trial. Adult patients with primary invasive, clinically node-negative T1-3 breast cancer and up to two SLN macrometastases were randomized 1:1 to completion ALND (standard) or its omission (intervention). Adjuvant treatment followed standards of care. The primary endpoint was overall survival (OS), requiring 190 deaths to conclude non-inferiority (upper one-sided 90% CI for the hazard ratio < 1.44) with ALND as the reference group. The secondary endpoint breast cancer-specific survival (BCSS) required 66 breast cancer deaths. Patient-reported outcomes were recorded 1, 3, and 5 years after randomization by the questionnaires Lymph-ICF (arm morbidity), EORTC QLQ-C30 and BR23 (health-related quality of life).
Results:
From 1/2015 to 12/2021, 2766 patients were randomized in 5 countries. The per-protocol population comprised 2540 patients (1205 randomized to ALND and 1335 to its omission). The median follow-up was 60.1 months (1.5-122.7 months). Questionnaire response rates were 81.3% and 74.6% at 3 and 5 years, respectively.
Overall, 196 patients died, 75 of whom due to breast cancer. Five-year OS was 93.4% (95% CI 91.9%-94.9%) in the ALND and 94.4% (95% CI 93.1%-95.7%) in the omission group, with a country-adjusted hazard ratio of 0.84 (95% CI 0.64-1.12). Five-year BCSS was 97.3% (95% CI 96.4%-98.3%) in the ALND and 97.8% (95% CI 97.0%-98.6%) in the omission group, with a country-adjusted hazard ratio of 0.86 (95% CI 0.55-1.34). Both endpoints fell significantly
(p = 0.238 for OS and p = 0.504 for BCSS) below the pre-specified non-inferiority margin.
Arm physical function according to the Lymph-ICF questionnaire was significantly better in the omission than the ALND group with a clinically relevant mean score difference of 6.14 at 3 years (95% CI 5.00-7.43, p < 0.001) and 5.71 at 5 years (95% CI 4.46-7.25, p < 0.001). Similarly, arm symptoms according to EORTC QLQ-BR23 were significantly more pronounced in the ALND than the omission group both after 3 (mean score 20.80+/-21.24 versus mean score 10.83+/-15.48, p < 0.001) and after 5 years (mean score 19.40+/-21.07 versus mean score 9.31+/-15.58, p < 0.001). Global health-related quality of life did not show any statistically significant differences after 3 and 5 years.
Conclusions:
Omission of completion ALND after a positive SLN biopsy is oncologically safe and mitigates postoperative patient-reported arm morbidity.
Citation:
J Clin Oncol 44, 2026 (suppl 17; abstr LBA503)
DOI:
10.1200/JCO.2026.44.17_suppl.LBA503
Abstract Disclosures:
PRESS RELEASE
Some Breast Cancer Patients With Sentinel Lymph Node Spread Can Safely Skip Axillary Lymph Node Dissection
*This summary includes updated data not reflected in the abstract.
May 30, 2026
ASCO Perspective Quote
“Lymphedema can be a devastating quality-of-life issue that alters a woman’s mobility, appearance, and self-esteem long after breast cancer treatment is complete. This rigorous, large-scale trial proves that we can safely skip invasive axillary node dissection in patients with limited nodal disease, and that by avoiding this additional surgery, we can drastically reduce long-term arm complications and improve arm function for breast cancer patients even years out from their diagnosis. These findings have the potential to simplify surgical management and meaningfully impact breast cancer survivorship for women throughout the world,” said Jane Lowe Meisel, MD, FACSO, medical oncologist at Winship Cancer Institute of Emory University and an ASCO Expert in breast cancer.
Study at a Glance
Focus Breast cancer that has spread to 1 to 2 sentinel lymph nodes
Population: 2,540 patients from Sweden, Denmark, Germany, Greece, and Italy.
Main Takeaway Omitting an axillary lymph node dissection (ALND) is safe for patients with breast cancer that has spread to 1 to 2 sentinel lymph nodes and can help them avoid lasting arm-related side effects.
Significance
Breast cancer is the most commonly diagnosed cancer for women in the U.S., accounting for about 1 in 3 of all new cancers diagnosed. The American Cancer Society (ACS) estimates that nearly 322,000 women will be diagnosed with breast cancer in the U.S. in 2026.
Up to 20% of breast cancers spread to the sentinel lymph nodes. If a sentinel lymph node biopsy shows cancer in the sentinel lymph nodes, it’s more likely that the cancer has spread to other lymph nodes, too. In this instance, an axillary lymph node dissection (ALND) might be done to remove additional lymph nodes from under the arm.
ALNDs are known to cause lasting arm problems, including pain, numbness, limited arm mobility, and lymphedema. According to the study’s authors, nearly 1 in 5 (19%) people who have an ALND report moderate problems with their arm function 5 years later, and 13% report severe or very severe problems.
Previous research has shown that avoiding an ALND may be safe for some people with breast cancer whose cancer has spread to the sentinel lymph nodes.
In this study, researchers wanted to look at whether it is safe for people who are getting a mastectomy or who have macrometastases, which are tumors that have spread to the sentinel lymph nodes and are larger than 2 millimeters.
ALEXANDRIA, Va. — Results from the phase 3 SENOMAC clinical trial found that omitting an axillary lymph node dissection (ALND) was safe for people with breast cancer that has spread to 1 or 1 sentinel lymph nodes, as it helped them avoid arm-related side effects known to impact quality of life. The research will be presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, taking place May 29 to June 2 in Chicago.
About the Study
“After previous trials, it was unclear whether the omission of ALND could also be offered to patients receiving a mastectomy or those with larger tumors. The key finding is that more axillary surgery in itself does not improve survival in these patients. This is extremely important because it means that axillary surgery should be seen as a diagnostic instrument, not a therapeutic tool,” said lead study author Jana de Boniface, MD, PhD, Department of Surgery, Capio St. Göran’s Hospital and Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.
The trial included 2,540 people with T1 to T3 breast cancer and up to 2 sentinel lymph node macrometastases. T1 to T3 tumors have not grown into the chest wall or skin, and they range in size from 0.1 centimeter to more than 5 centimeters. The median age of study participants was 61. Most participants had estrogen receptor-positive cancer (93.6%), and slightly over 1 in 3 had a mastectomy (36.3%).
After receiving a SLNB that showed up to 2 macrometastases, the participants were randomly assigned either to receive an ALND (1,205 people) or not to receive an ALND, called the omission group (1,335 people). Both groups received adjuvant treatment according to the current standards of care, which often includes radiation therapy to the regional lymph nodes.
To assess arm-related side effects, the participants responded to questionnaires 1 year, 3 years, and 5 years after they were randomly assigned to a treatment group. These included:
The Lymph-ICF questionnaire, which asks questions related to the impact of arm lymphedema, such as how well a person can lift heavy objects or drive a car. The participants rated their problems on a scale of 0 to 10, resulting in a total score of 0 to 100. A score of 0 means no arm problems, and a score of 100 means the most severe arm problems.
The EORTC QLQ-BR23 questionnaire, which asks questions related to breast cancer-specific side effects, including arm symptoms. Scores from this questionnaire range from 0 to 100, with a higher score meaning more symptoms.
Key Findings
After a median follow-up of 60.1 months:
The 5-year overall survival rate was similar between groups, with 93.4% of participants still alive at 5 years in the ALND group compared to 94.4% of participants in the omission group.
The 5-year breast cancer-specific survival was 97.2% in the ALND group vs. 97.9% in the omission group.
Overall, 203 participants died, 74 of them from breast cancer.
In addition, the participants who did not have an ALND reported significantly better arm function at 1, 3, and 5 years after treatment than those who had an ALND:
Based on the Lymph-ICF questionnaire scores, those who did not receive an ALND had an average score difference of 10.64 at 1 year, 10.73 at 3 years, and 10.75 at 5 years, indicating better self-reported arm function.
Based on the EORTC questionnaire scores, fewer arm problems were reported in the omission group. At 1 year, there was an average score difference of 10.90. At 3 years, the average score difference was 9.86, and at 5 years, it was 10.02.
Response rates to the questionnaires were 83% at 1 and 3 years and 81% at 5 years.
Next Steps
The researchers are starting another randomized trial, called SENOMAC-ULTRA, to compare ALND against targeted axillary dissection, which removes significantly fewer lymph nodes, in people with known spread of the cancer to the lymph nodes in the armpit. They are also conducting the randomized T-REX trial to evaluate the omission of nodal radiation therapy in patients with estrogen receptor-positive breast cancer and 1 to 2 sentinel lymph node metastases who do not receive an ALND.
This study was funded by the Swedish Cancer Society, the Swedish Scientific Council, the Nordic Cancer Union, and the Swedish Breast Cancer Association.