SLN surgery alone effective for lymph node negative breast cancer patients
MedWire News: Sentinel lymph node (SLN) surgery is an effective alternative to axillary lymph node dissection (ALND), offering equivalent survival rates in breast cancer patients with clinically negative lymph nodes, researchers report.
"SLN surgery was designed to minimize the side-effects of lymph-node surgery but still offer outcomes equivalent to ALND," explain David Krag (University of Vermont, Burlington, USA), and colleagues.
To investigate whether SLN surgery achieves these aims, Krag and team set up the National Surgical Adjuvant Breast and Bowel Project (NSABP) trial B-32.
They recruited 5611 women with invasive breast cancer from 80 centers in Canada and the USA, and randomly assigned them to receive SLN resection plus ALND or SLN resection alone.
Patients in both groups who had pathologically negative SLNs (n=3986) were monitored at 4-6-month intervals for an average of 8 years.
During that time there were 140 (7.1%) deaths among 1975 patients who underwent SLN resection plus ALND, and 169 (8.4%) deaths among 2011 patients who underwent SLN resection alone, report Krag and team.
Overall survival, disease-free survival, and regional disease control did not differ significantly between the two groups, they say.
Specifically, the 8-year overall and disease-free survival estimates were 91.8% and 82.4%, respectively, among patients who underwent SLN resection plus ALND, compared with 90.3% and 81.5%, respectively, among patients who received SLN resection only.
In addition, there were eight regional-node recurrences as first events in the SLN resection plus ALND group, and 14 in the SLN resection-only group.
Krag et al note that acute adverse side effects were limited to allergic reactions in 46 patients, mostly related to the blue dye used in the SLN biopsy procedure.
Writing in The Lancet Oncology the authors conclude: "When the SLN is negative, SLN surgery alone with no further ALND is an appropriate, safe, and effective therapy for breast cancer patients with clinically negative lymph nodes."
In an accompanying comment, John Benson, from the University of Cambridge in the UK, said that this seminal paper: "Vindicates contemporary practice of SLN biopsy and provides support for a reduction in extent of axillary surgery for most patients with breast cancer."
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By Laura Dean