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 the removal of both marked and sentinel lymph nodes (SLNs). The aim was to investigate the optimization of TAD localization techniques after NAT in breast cancer patients.

METHODS

From November 2020 to 2022, the authors prospectively enrolled 107 lymph node-positive breast cancer patients at Shandong Cancer Hospital, all of them received complete cycles of NAT. Before treatment, patients were randomly divided into three groups: group A, marked node with clip ( n =34); group B, marked node with 125 I seed (n=32); and group C, marked node with both a clip and 125 I seed ( n =41). Dual tracers were used to search for SLNs after NAT. The primary 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 groups 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 tracers, radiolabeled tracers, 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 the inexpensive and high detection rate of 125 I seeds, it is recommended to use 125 I seeds for localizing metastatic nodes in neoadjuvant setting. The TAD guided by dye tracer is also a feasible option for axillary de-escalation surgery after NAT in countries or regions without access to radiolabeled colloid.