TOPLINE:
Omitting axillary lymph node dissection does not increase the risk for recurrence or compromise 5-year overall survival outcomes in patients with early-stage, node-negative breast cancer with sentinel-node metastases undergoing surgery and radiation therapy.
METHODOLOGY:
- A growing body of evidence has indicated that patients with one or two positive sentinel nodes undergoing breast-conserving surgery and radiation therapy can skip axillary lymph node dissection and achieve similar outcomes compared with patients receiving axillary dissection.
- However, these earlier studies had notable limitations, such as limited statistical power, uncertain nodal radiotherapy target volumes, and minimal data on relevant clinical subgroups.
- To fill the gaps in the literature, the researchers conducted a trial with a large, inclusive cohort of patients with node-negative stage T1-T3 breast cancer who had one or two sentinel-node macrometastases and had undergone a mastectomy or breast-conserving surgery.
- The trial randomized 2540 patients to either completion axillary lymph node dissection (n = 1205) or sentinel-node biopsy only (n = 1335). Nearly 90% of patients received adjuvant radiation therapy, and the majority also received systematic therapy.
- Earlier recurrence-free survival findings and patient-reported outcomes were reported last December. The researchers now reported overall survival findings as well as secondary endpoints of breast cancer-specific survival.
TAKEAWAY:
- The researchers reported 191 recurrences or deaths over a median follow-up of 46.8 months; 62 patients (4.6%) in the sentinel-node biopsy–only group died, and 69 patients (5.7%) in the dissection group died.
- The biopsy-only group had an estimated 5-year overall survival of 92.9% compared with 92.0% in the dissection group and an estimated 5-year breast cancer-specific survival of 97.1% vs 96.6% in the dissection group.
- The estimated 5-year recurrence-free survival was 89.7% in the biopsy-only group vs 88.7% in the dissection group (hazard ratio [HR], 0.89; 95% CI, 0.66-1.19).
- This non-inferior difference held across all prespecified patient subgroups, except in patients with estrogen receptor-positive, human epidermal growth factor receptor 2-positive disease, in which sentinel biopsy alone appeared to be better (HR, 0.26).
IN PRACTICE:
"This trial provides robust evidence that the omission of completion axillary-lymph-node dissection was safe in patients with clinically node-negative T1, T2, or T3 breast cancer and one or two sentinel-node macrometastases who received adjuvant systemic treatment and radiation therapy according to national guidelines," the authors concluded.
"It is clear that the role of axillary dissection is rapidly disappearing," wrote Kandace P. McGuire, MD, of Virginia Commonwealth University, Richmond, Virginia, in an accompanying editorial. "However, axillary staging continues to be vital with regard to decisions about appropriate breast cancer therapy."
SOURCE:
This work, led by Jana de Boniface, MD, PhD, from Karolinska Institute, Stockholm, Sweden, was published online in the New England Journal of Medicine, alongside an accompanying editorial by Kandace P. McGuire, MD.
LIMITATIONS:
The study limitations include unavailable radiation therapy details for comparison, low male recruitment hindering sex-based analysis, short follow-up for luminal subtype breast cancer, unmet enrollment targets, and higher withdrawal rates in the dissection group.
DISCLOSURES:
This study was supported by the Swedish Research Council, Swedish Cancer Society, Nordic Cancer Union, and Swedish Breast Cancer Association. Oreste Davide Gentilini reported receiving consultancy fees from various pharmaceutical companies outside this work.