Incorporating Lymphovenous Anastomosis in Clinically Node-Positive Women Receiving Neoadjuvant Chemotherapy: A Shared Decision-Making Model and Nuanced Approached to the Axilla.

Introduction: Lymphedema remains a risk for 13-34% of breast cancer patients who require an axillary dissection (ALND) and radiation. Immediate lymphovenous anastomosis (LVA) may mitigate lymphedema by up to 30% by restoring the physiologic lymphatic drainage immediately after ALND. Currently, completion of ALND (cALND) versus radiation after neoadjuvant therapy (NAC) is being addressed by the Alliance A11202 trial, leaving a paucity of data to guide practice. Our study describes the implementation process of LVA into clinical practice after NAC for node-positive breast cancer in the current clinical context.

Methods: We reviewed a prospective database of LVA in node-positive patients (cT1-4,Nany) who received NAC followed by axillary surgery ± immediate LVA from October 2021 to 2022. The evolution of the surgical approach is described. Specifically, patients who downstaged to clinically negative nodes post-NAC were offered targeted SLNB with dual-tracer and intraoperative frozen section (FS). Patients were reminded that the standard of care for any node positive is cALND. Immediate cALND with LVA was performed for grossly positive nodes or all positive SLNs; cALND was omitted for those with negative SLNs. For a microscopic disease on a frozen section, a shared decision was made pre-operatively, given each patient's differing valuations of the benefit and risks of cALND ± LVA versus no cALND with planned regional radiation postoperatively. LVA was offered as an option as part of our institutional evaluation of the procedure.

Results: A total of 15 patients were included; the mean age was 49.9 (range 32-75) with stage IIA to IIIB breast cancer. Of these, 6 (40%) were triple negative, 5 (33.3%) HER-2 positive, and 4 (26.7%) ER/PR+ HER-2 negative. There were 13 women (86.7%) who had persistent axillary adenopathy based on clinical and/or ultrasound assessment, with 8 patients proceeding directly to ALND with LVA. Among these patients, 3 (37.5%) had pathologic nodal disease, and 5 (62.5%) were node negative, confirming the limitations of pre-operative imaging. As a result, the subsequent 7 (46.7%) underwent targeted SLNB with FS, with 3 patients (42.9%) avoiding an ALND as a result of a negative FS. A total of 4 patients (57.1%) had 1 or more positive lymph nodes on FS: 3 proceeded with a cALND and LVA, and 1 patient (14.2%) opted for no cALND based on a pre-operative discussion and received adjuvant radiation and chemotherapy. Of the 11 patients who underwent ALND and LVA, 1 patient (9.1%) developed lymphedema at 6.9 months following their surgery. The accuracy, sensitivity, and specificity of pre-operative US were 46.7%, 85.7%, and 12.5% and intraoperative FS were 88.0%, 72.7%, and 100%, respectively.

Conclusions: As adjuvant nodal radiation and systemic therapy continue to improve, the benefit of a cALND in patients with the limited residual disease remains unclear as we await the outcomes from clinical trials. In the era of clinical uncertainty, we propose a nuanced approach to the axilla by utilizing a shared decision model with patients, incorporating targeted SLNB with FS and completion node dissection when required and desired by the patient, coupled with LVA in a simple stepwise treatment pathway.