Axilla lymph node dissection can be safely omitted in patients with 1–2 positive sentinel nodes receiving mastectomy: a large multi-institutional study and a systemic meta-analysis

Purpose This study aimed to evaluate whether axillary lymph node dissection (ALND) can be omitted in patients with 1–2 positive sentinel lymph nodes (SLNs) who received total mastectomy (TM). Methods Consecutive breast cancer patients with 1–2 positive SLNs were retrospectively reviewed from a multi-institutional database. Patients were divided into sentinel lymph node biopsy (SLNB) group and ALND group. Administration of adjuvant chemotherapy and survival were compared between groups. To further verify the results, a meta-analysis was also conducted. Results Among the 1161 enrolled patients, 893 (76.9%) received ALND and 268 (23.1%) underwent SLNB alone. Administration of chemotherapy was comparable between the two groups (91.1% vs. 90.6%, P = 0.798), which was consistent in TM ( P = 0.638) and BCS cohort ( P = 0.576). After a median follow-up of 36 months, no significant difference was observed between the two groups in recurrence-free survival ( P = 0.583) regardless of surgery of breast. During further meta-analysis, 13 out of 4733 relative studies reported the association of axillary surgery and disease-free survival (DFS) or overall survival (OS) in 1–2 positive SLNs patients. Pooled analysis showed no difference in adjusted DFS (HR 0.84, 95% CI 0.70–1.02) or OS (HR 1.02, 95% CI 0.93–1.11) between SLNB and ALND groups. Survival benefit of ALND remained non-significant after restricting the analysis in four studies with patients only receiving BCS, or in three studies with patients only receiving TM. Conclusion Further ALND does not impact adjuvant chemotherapy administration or disease outcome in breast cancer patients with 1–2 positive SLNs treated with TM.