What Are the Clinical Implications?
The current study findings make an important contribution to the effort to de-escalate axillary surgery in early breast cancer, Dr. Giannakou said during the interview. Although SLNB is less morbid than axillary lymph node dissection, the lymphedema risk still exists, and identifying which patients actually benefit from SLNB is critical, he said.
“In our multidisciplinary team, we are working to define selection criteria for postmenopausal patients with HR+HER2- breast cancer who would have met eligibility criteria for the SOUND trial and for whom omission of SLNB would not change adjuvant treatment considerations,” he said.
“Breast surgeons have been moving towards less aggressive axillary surgery based on evidence showing its safety in specific patient cohorts, particularly those with low-risk factors such as older age (70 years and above) and early-stage hormone receptor-positive breast cancer,” Sarah Blair, MD, professor and vice chair in the department of surgery at UC San Diego Health, said in an interview.
“The Choosing Wisely recommendations, issued by the Society of Surgical Oncology, advise against routine use of sentinel lymph node biopsy in women aged 70 and older with early-stage hormone receptor–positive breast cancer; these recommendations are based on clinical trials demonstrating oncologic safety in this population,” said Dr. Blair, who was not involved in the SOUND trial or the current study.
The data from the new study are encouraging and highlight the generalizability of the SOUND results, Mediget Teshome, MD, chief of breast surgery at UCLA Health, said in an interview. The results help to define a low-risk group of patients for which sentinel node staging may be omitted, after multidisciplinary discussion to ensure that nodal staging will not impact adjuvant systemic therapy or radiation decision-making, said Dr. Teshome, who was not involved in the SOUND trial or the current study.
What Are the Limitations of the SOUND trial and the New Study?
The current study limitations included its design having been a retrospective review of a prospective database with selection bias, lack of standard criteria for preoperative axillary ultrasound, and the lack of SLNB for many patients older than 70 years based on the Choosing Wisely criteria, Dr. Giannakou said in the press briefing.
“Despite the evidence supporting axillary surgery de-escalation, it can be challenging for surgeons to change their practice based on a single study,” Dr. Blair said an interview. However, the SOUND trial findings support current evidence, giving surgeons more confidence to discuss multidisciplinary treatment options, she said.
What Additional Research is Needed?
“Longer follow-up is needed to make definitive conclusions about the oncologic outcomes of axillary surgery de-escalation in this patient population,” said Dr. Blair. “Given that slow-growing tumors are involved, the time to recurrence may extend beyond the typical follow-up period of three years.
“Ongoing research and collaboration among multidisciplinary teams are essential to ensure optimal treatment decisions and patient outcomes,” she emphasized.
Dr. Giannakou, Dr. Blair, and Dr. Teshome had no financial conflicts to disclose.