CADONOT: Comparing axillary dissection or not in breast cancer surgery

Sentinel lymph node biopsy (SLNB) is the gold standard for the axillary evaluation of clinically node-negative early breast cancer. The ACOSOG Z0011 study demonstrated the safety of omitting axillary dissection for limited SLNB disease, with other trials confirming SLNB alone or with axillary radiotherapy (AR) as non-inferior.

We followed PRISMA guidelines and registered at PROSPERO. Using Medline, Embase, and Cochrane, we reviewed randomized controlled trials (2010-2024). Outcomes, including 5-, 8-, and 10-year OS, DFS, recurrence rates, and lymphedema, were analyzed with R software and assessed for bias (Cochrane RoB) and evidence quality (GRADE). The focus was ALND vs. SLNB, alone or with AR, in cT1-T3 BC with 1-2 metastatic SLNs.

Thirteen articles from seven randomized controlled trials (RCTs) were included, covering 7338 women with a follow-up period of 2.8-10 years. SLNB was associated with a 65 % lower risk of lymphedema than ALND, with no significant differences in the 5-, 8-, or 10-year OS, DFS, or recurrence rates. A meta-analysis comparing micrometastasis and macrometastasis showed no impact on outcomes, indicating that ALND may be unnecessary in either case. Recurrence rates also did not differ between SLNB and ALND, reinforcing SLNB's significantly lower lymphedema risk of SLNB.

This systematic review and meta-analysis support SLNB as a safe and effective alternative to ALND in early-stage BC with 1-2 positive SLNs, providing comparable survival and recurrence outcomes, with fewer complications.