Nearly 10 years of follow-up from a large clinical trial have confirmed that axillary dissection is not necessary in patients with early breast cancer and a minimal or moderate tumor burden in the sentinel nodes.
“Up to the 1990s, the surgical treatment of invasive breast cancer included axillary lymph-node dissection,” wrote study authors led by Viviana Galimberti, MD, of the European Institute of Oncology in Milan. “However, the short-term and long-term side-effects of axillary dissection were always of concern.”
Previously, the 5-year results of the International Breast Cancer Study Group (IBCSG) 23-01 trial showed no differences in disease-free survival (DFS), overall survival (OS), or recurrence between patients who did or did not receive axillary dissection; other studies have also showed similar results. The new report extends that analysis out to a median follow-up of 9.7 years; the results were published in Lancet Oncology.
The trial included 934 patients randomized to no axillary dissection (469 patients) or to axillary dissection (465 patients) between 2001 and 2010. All patients had breast cancer with one or more metastatic sentinel nodes, all of which were 2 mm in size or smaller.
The DFS rate at 10 years was 76.8% without axillary dissection, and 74.9% with the procedure, for a hazard ratio (HR) of 0.85 (95% CI, 0.65–1.11; P = .24; P for noninferiority = .0024). There were no differences between the groups with regard to cumulative incidence of breast cancer events, with a 10-year incidence of 17.6% with no dissection and 17.3% with dissection, for an HR of 0.98 (95% CI, 0.71–1.36; P = .92). The 10-year OS rate was 90.8% with no dissection and 88.2% with dissection, for an HR of 0.78 (95% CI, 0.53–1.14; P = .20).
Long-term surgical adverse events were monitored only until year 5, so the updated analysis is similar to what was previously published. Sensory neuropathy, lymphedema, and motor neuropathy were more frequent in the axillary dissection group.
“This 10-year follow-up study provides additional, high-level evidence that omission of axillary dissection in patients with minimal disease burden in the sentinel nodes is an acceptable treatment,” the authors concluded.
Henry Kuerer, MD, PhD, executive director of the breast programs at the University of Texas MD Anderson Cancer Center in Houston, who was not involved in the research, told Cancer Network that “many US surgeons are now also avoiding performing additional axillary surgery when only micrometastases are found. The current National Comprehensive Cancer Network guidelines also seem to support this.”