The feasibility of targeted axillary dissection for breast cancer axillary surgery de-escalation after neoadjuvant therapy: A prospective cohort study

Purpose: Targeted axillary dissection (TAD) after neoadjuvant therapy (NAT) includes removing of marked and sentinel lymph nodes (SLNs). The aim was to investigate the optimization of TAD localization techniques after NAT among breast cancer patients. Methods: From November 2020 to 2022, we prospectively enrolled 107 lymph node-positive breast cancer patients in XX Hospital and received complete cycles of NAT. Patients were randomly divided into the following 3 groups before treatment: group A, marked node with clip (n=34); group B, marked node with 125 I seed (n=32); and group C, marked node with clip and 125 I seed (n=41). Dual tracers were used to search for SLNs after NAT. The main endpoint was the detection rate of marked nodes and false-negative rate (FNR). Results: The detection rates using the TAD localization technique were 82.6% (28/34), 100% (32/32), and 100% (41/41) for groups A, B, and C, respectively ( P >0.05). The FNR rates were 15.8%, 5.9%, and 5.6% among group A, B, and C, respectively ( P >0.05). The FNR rates in cN1 patients were 5.1%, 2.7%, and 2.6%, among these three groups, respectively ( P >0.05). The change in distance between 125 I seeds and clips in axillary lymph nodes was <3 mm. The FNR rates of TAD guided by dye tracer, radiolabeled tracer, and dual tracers were 5.4%, 5.2%, and 3.4%, respectively ( P >0.05). The negative predictive values were 93.0%, 93.0%, and 95.2%, respectively ( P >0.05). Conclusion: Considering inexpensive and detect rate of 125 I seeds, it is recommended that placement of 125 I seeds to localize metastatic nodes in neoadjuvant setting. The TAD guided by dye tracer is also feasible for axillary de-escalation surgery after NAT in countries or regions without radiolabeled colloid.