Ten-Year Oncologic Outcomes in T1-3N1 Breast Cancer After Targeted Axillary Sampling: A Retrospective Study

Targeted axillary dissection: worldwide variations in clinical practice

PURPOSE

Targeted axillary dissection (TAD) for the axillary staging of clinically node-positive (cN +) breast cancer patients converting to clinically node negative post neoadjuvant chemotherapy (NAC), has gained popularity due to its minimal false negative rate and low arm morbidity. The aim of this study is to shed more light on the variation in the clinical practice globally in terms of indications and perceived limitations of TAD.

METHODS

A panel of expert breast surgeons constructed a structured questionnaire comprising of 18 questions and asked surgeons worldwide for their opinions and routine practice on TAD. The questionnaire was electronically distributed and answers were collected between May 1st and August 1st 2022.

RESULTS

Responses included 137 entries from 36 countries. Of them, 73.7% consider TAD for cN + patients planned to receive NAC. Among them, the greatest number of respondents (45%) perform the procedure for tumours up to T3, whereas 27% regardless of T-stage. The majority (42%) perform TAD on patients with 1-3 positive nodes and only 30% consider TAD when matted nodes are present. HER2 positive and Triple Negative subtypes are more likely to undergo TAD than Luminal A and B (86%, 79.1%, 39.5%, and 62.8%, respectively). Maximum acceptable lymph node burden is median 3 nodes for any subtype with a tendency to accept more positive nodes for Triple Negative.

CONCLUSION

This study demonstrates the differences in current practice regarding TAD as well as the fact that the biology of the tumour heavily affects the method of axillary staging.

Ideal marker for targeted axillary dissection (IMTAD): a prospective multicentre trial

BACKGROUND

Targeted axillary dissection (TAD) is an established method for axillary staging in patients with breast cancer after neoadjuvant chemotherapy (NAC). TAD consists of sentinel lymph node biopsy and initially pathological lymph node excision, which must be marked by a reliable marker before NAC.

METHODS

The IMTAD study is a prospective multicentre trial comparing three localisation markers for lymph node localisation (clip + iodine seed, magnetic seed, carbon suspension) facilitating subsequent surgical excision in the form of TAD. The primary outcome was to prospectively compare the reliability, accuracy, and safety according to complication rate during marker implantation and detection and marker dislodgement.

RESULTS

One hundred eighty-nine patients were included in the study-in 135 patients clip + iodine seed was used, in 30 patients magnetic seed and in 24 patients carbon suspension. The complication rate during the marker implantation and detection were not statistically significant between individual markers (p = 0.263; p = 0.117). Marker dislodgement was reported in 4 patients with clip + iodine seed localisation (3.0%), dislodgement did not occur in other localisation methods (p = 0.999). The false-negativity of sentinel lymph node (SLN) was observed in 8 patients, the false-negativity of targeted lymph nodes (TLN) wasn´t observed at all, the false-negativity rate (FNR) from the subcohort of ypN + patients for SLN is 9.6% and for TLN 0.0%.

CONCLUSION

The IMTAD study indicated, that clip + iodine seed, magnetic seed and carbon suspension are statistically comparable in terms of complications during marker implantation and detection and marker dislodgement proving their safety, accuracy, and reliability in TAD. The study confirmed, that the FNR of the TLN was lower than the FNR of the SLN proving that the TLN is a better marker for axillary lymph node status after NAC.

TRIAL REGISTRATION

NCT04580251. Name of registry: Clinicaltrials.gov. Date of registration: 8.10.2020.