Impact of immediate versus delayed axillary node dissection on surgical outcomes in breast cancer patients with positive sentinel nodes: Results from American College of Surgeons Oncology Group trials Z0010 and Z0011

Purpose: Patients with breast cancer metastasis to the sentinel lymph nodes (SLNs) generally undergo completion axillary lymph node dissection (cALND), either concurrently with SLN biopsy or at a second procedure. The impact of the timing of cALND on pathologic results and complications in these patients has not been examined. Patients and Methods: We examined outcomes from SLN-positive patients in American College of Surgeons Oncology Group (ACOSOG) trials Z0010 and Z0011. Pathologic data examined included primary tumor characteristics, total number of SLNs recovered, positive SLN(s) and non-SLN(s) identified. Complications assessed included axillary seroma, paresthesia, arm morbidity and range of motion, and lymphedema. Results: A total of 1,003 assessable patients with SLN metastasis had immediate (n = 425) or delayed (n = 578) cALND. The median number of SLNs and axillary LNs removed were the same between groups. Patients who had immediate cALND more often had larger tumors, SLN metastasis identified intraoperatively, two or more positive SLNs, and higher pathologic N stage. Axillary paresthesia, seroma, and impaired extremity range of motion were more common in the immediate group during the early postoperative period, but not at later time points. There was no difference in lymphedema at any time point. Conclusion: In ACOSOG trials Z0010 and Z0011, LN recovery and long-term complications were similar after either delayed or immediate cALND for patients with metastasis to SLNs. Patients who undergo immediate cALND experience more short-term morbidity. With respect to staging and complications, there is no clear detriment for patients with a positive SLN who undergo a second procedure for cALND.