Axillary management decisions made during surgery may be associated with aggressive treatment of limited nodal disease, according to data presented at a press briefing at the 2023 American Society of Breast Surgeons Annual Meeting.1
Results of a large National Cancer Database study revealed that intraoperative pathology assessment significantly increased the use of both axillary lymph node dissection and axillary radiation therapy in patients with clinically node-negative breast cancer who were undergoing upfront mastectomy with one to two positive sentinel lymph nodes. Omission of routine intraoperative pathology assessment may help to minimize axillary overtreatment and associated morbidity in this population, authors of the study noted.
Olga Kantor, MD, MS
“The results of the study are clear—a large number of women are potentially being overtreated when axillary management decisions are made intraoperatively,” said Olga Kantor, MD, MS, a breast surgical oncologist at Brigham and Women’s Hospital and Dana-Farber Cancer Center, and Assistant Professor of Surgery at Harvard Medical School. “This study suggests that in appropriate cases, surgeons should delay axillary lymph node dissection decision-making until a later time to avoid overtreating patients.”
As Dr. Kantor reported, the AMAROS clinical trial established the safety of axillary observation or axillary radiation therapy as an alternative to axillary lymph node dissection in patients with clinically node-negative breast cancer who have one to two positive sentinel lymph nodes.2 However, controversy remains about the optimal axillary management in similar patients undergoing mastectomy.
According to Dr. Kantor, intraoperative pathology assessment is a strategy that can help avoid the need to return to the operating room for additional axillary surgery by checking the sentinel lymph nodes during surgery. However, acting on intraoperative pathology does not allow for multidisciplinary discussion, and mastectomy patients who undergo axillary lymph node dissection may still be recommended for postmastectomy radiation therapy and possibly the addition of axillary radiation therapy.
“This dual approach may result in axillary overtreatment in patients who may otherwise have been eligible for axillary radiation alone,” said Dr. Kantor, who noted this practice pattern variation exists.
A 2021 survey of the American Society of Breast Surgeons was conducted on the approach to the clinically node-negative axilla in patients undergoing upfront mastectomy. The survey results showed that 52% of responding surgeons were routinely using intraoperative pathology to assess the sentinel lymph nodes, and 78% of those routinely performed axillary lymph node dissection if the sentinel lymph node was positive.3
For this study of the National Cancer Database, Dr. Kantor and colleagues included AMAROS-eligible patients who had undergone upfront mastectomy and sentinel lymph node biopsy between 2018 and 2019 and were found to have one to two positive sentinel lymph nodes. The researchers examined axillary management patterns by the size of nodal metastases and the use of intraoperative pathology. Intraoperative pathology assessment was defined as either “not done or not acted on” if axillary lymph node dissection was either not performed or performed later than sentinel lymph node biopsy or “done or acted on” if sentinel lymph node biopsy and axillary lymph node dissection were performed on the same day. Axillary radiation therapy was defined as postmastectomy radiation, including radiation to the draining lymph nodes.
A Link to Aggressive Axillary Treatment
In the overall population, approximately 33% of patients underwent axillary observation with no further treatment of the axilla, whereas 26% and 23% underwent axillary lymph node dissection alone and axillary radiation therapy alone, respectively. When the results were stratified by the performance of intraoperative pathology, however, researchers observed different findings, said Dr. Kantor. She noted that intraoperative pathology assessment was performed and acted on in approximately 37% of AMAROS-eligible patients undergoing mastectomy.
“In patients where intraoperative pathology was not performed or not acted on, just 5% of patients went on to receive both axillary lymph node dissection and axillary radiation,” Dr. Kantor reported. “Conversely, in those patients for whom intraoperative pathology was performed and acted on, 41% went on to receive both axillary lymph node dissection and axillary radiation.”
The researchers then used multivariable analysis adjusting for patient tumor and treatment characteristics to identify predictors of receiving both axillary lymph node dissection and axillary radiation therapy. According to Dr. Kantor, the use of intraoperative pathology was “by far the greatest predictor of aggressive axillary treatment.” Patients who received an intraoperative pathologic assessment were approximately nine times more likely to receive both axillary lymph node dissection and axillary radiation therapy.
Expert Point of View
Sarah Blair, MD, FACS, Professor and Vice Chair, Division of Breast Surgery, UC San Diego, told The ASCO Post that previous research has shown that radiation therapy for microscopic disease in the lymph nodes is effective in controlling axillary disease with less risk of lymphedema or arm swelling. According to Dr. Blair, the main point of this abstract is to “demonstrate that if surgeons test the lymph nodes during the cancer operation, they are more likely to do more aggressive surgery of axillary dissection and subsequent radiation.”
Sarah Blair, MD, FACS
“However, if surgeons do not test the lymph nodes by frozen section during the initial operation, they are more likely to do a multidisciplinary discussion prior to considering more aggressive surgery,” Dr. Blair continued. “Then, perhaps, we can save patients from potential complications of arm swelling from complete axillary dissection and radiation.”
DISCLOSURE: Dr. Kantor reported no conflicts of interest. Dr. Blair reported no conflicts of interest.
1. Pride R, Glass C, Nakhlis F, et al: 2023 American Society of Breast Surgeons Annual Meeting. Abstract. Presented April 27, 2023.
2. Bartels SAL, Donker M, Poncet C, et al: J Clin Oncol 41:2159-2165, 2023.
3. Cortina CS, Bergom C, Craft MA, et al: Ann Surg Oncol 28:5568-5579, 2021.