# Oncological Feasibility of Conservative Axillary Surgery (Opinion Article): Tailored Axillary Surgery vs. Axillary Reverse Mapping-Guided Axillary Lymph Node Dissection

## TL;DR

This paper reviews the cancer safety of less invasive axillary surgery techniques and their potential to reduce side effects without increasing recurrence risk.

## Contribution

The paper evaluates the oncological feasibility of tailored axillary surgery and ARM-guided ALND based on current literature.

## Key findings

- ALND after TAS found additional involved nodes in 60–70% of patients.
- ARM nodes were involved in 15.7–64.7% of patients after conventional ALND.
- Postoperative radiotherapy may prevent recurrence in patients with microscopic residual disease.

## Abstract

Conventional axillary lymph node dissection (ALND) is associated with postoperative morbidities, including arm lymphedema, seroma, reduced shoulder mobility and local sensory dysfunction. Sentinel lymph node (SLN) biopsy has been introduced for assessing axillary nodal status in clinically node-negative (cN0) patients. However, ALND continues to be indicated for staging purposes and regional control in clinically node-positive (cN+) patients. Tailored axillary surgery (TAS) and axillary reverse mapping (ARM)-guided ALND have been developed to avoid arm lymphedema without increasing a risk of axillary recurrence. However, because TAS and ARM-guided ALND are much less radical than conventional ALND, their oncological feasibility remains a crucial consideration. For conventional ALND performed after TAS, additional involved nodes were found in 60–70% of patients. ARM nodes also were involved in 15.7–64.7% of patients who underwent conventional ALND. In this context, postoperative radiotherapy may be effective in preventing axillary recurrence in patients with low-volume (microscopic) additional nodal disease. And palpable suspicious axillary lymph nodes should be removed, not only in TAS but also in ARM-guided ALND. However, the majority of breast cancers are hormone receptor-positive and exhibit late recurrence. Therefore, we await the long-term results of prospective randomized clinical trials comparing TAS and ARM-guided ALND with conventional ALND to establish oncological safety of these procedures.

Background: Tailored axillary surgery (TAS) and axillary reverse mapping (ARM)-guided axillary lymph node dissection (ALND) have been developed to avoid arm lymphedema without increasing a risk of axillary recurrence. However, the oncological feasibility of TAS and ARM-guided ALND remains a crucial consideration. Methods: This article reviewed the oncological feasibility of TAS and ARM-guided ALND based on the current literature. Results: For ALND performed after TAS, additional involved nodes were found in 70% of upfront surgery patients and 60% of neoadjuvant chemotherapy (NAC) patients. ARM nodes were also involved in up to 64.7% of patients after ALND. However, it is not necessary to preserve all ARM nodes and lymphatics because multiple ARM lymphatic pathways exist. Selective preservation of ARM nodes closest to the axillary vein significantly reduced the incidence of involved ARM nodes (from 64.7% to 15.7%). Conclusions: TAS and ARM-guided ALND remain much less radical than ALND. However, residual nodal disease after TAS or ARM-guided ALND does not always develop axillary recurrence. Postoperative irradiation is effective in achieving local control in patients with low-volume (microscopic) residual nodal disease after TAS or ARM-guided ALND. We await the long-term results of prospective randomized clinical trials comparing TAS and ARM-guided ALND with conventional ALND.