Accuracy of sentinel node mapping in patients with biopsy-proven metastatic axillary lymph nodes and upfront surgery: preliminary results of the Multimodal Targeted Axillary Surgery (MUTAS) trial

Abstract

Background: Some studies suggested that the patients included in the Z0011 trial may represent patients with ultrasound-negative axillary nodes and axillary invasion diagnosed by sentinel node (SN) biopsy.Nevertheless, the National Comprehensive Cancer Network (NCCN) guidelines recommend SN mapping if 1 or 2 suspicious lymph nodes are identified on axillary ultrasound (AU). The aim of this preliminary phase of the Multimodal Targeted Axillary Surgery (MUTAS) trial was to establish the accuracy of SN mapping in patients with axillary involvement undergoing upfront surgery.Methods: Between September 2019 and March 2022, we recruited patients with biopsy-proven metastatic axillary nodes and upfront surgery from a single center. We performed SN mapping in these patients before the surgical intervention, which included axillary lymph node dissection. The biopsy-proven metastatic node, SNs and the remaining axillary nodes were excised separately. SN status was considered representative of the status of the remaining axillary nodes. We calculated the sensitivity, specificity, negative predictive value and positive predictive value of the SN, overall and in patients with palpable nodes, in those with non-palpable nodes and an AU leading to diagnosis of axillary involvement, in those with 1 or 2 suspicious nodes on AU, and in patients with a single suspicious node on AU. We evaluated clinical, imaging and pathology features as predictors of the status of the remaining axillary nodes, false-negatives, and false-positives. Results:We included 25 patients in this phase. The false-negative rate of SN mapping was 28% overall, 21.42% for patients with palpable nodes, 36.36% for patients with non-palpable nodes and an AU diagnosis of axillary involvement, 28.75% for those with 1 or 2 suspicious nodes on AU, and 15.38% in patients with a single suspicious node on AU. The negative predictive value was highest in patients with a single suspicious node on AU (75%). The only significant predictive factor was that FN showed a higher Ki67 index score.Conclusions: In this study, SN mapping was not reliable in patients with biopsy-proven metastatic axillary

Can targeted axillary dissection reliably advise de-escalation of completion axillary lymph node dissection?

“…These guidelines are based on the ACOSOG Z0011 data. Vernet-Tomás et al compare their study results to those of the Z0011 trial; however, there are some key differences between the two studies including the high proportion of patients in this study with clinically palpable axillary metastases (14/25) and a larger median tumor size of 22.55 mm ( 1 ). Both factors are associated with an increased the tumor burden within the axilla.…”

“…In the manuscript of Gland Surgery , Vernet-Tomás et al report their experience evaluating the utility and reliability of targeted axillary dissection (TAD) to predict the remaining axillary tumor load in clinically node positive patients undergoing upfront surgery ( 1 ). This prospective study included 25 patients with biopsy-proven metastatic axillary lymph nodes who underwent upfront surgery from September 2019 to March 2022.…”

Axillary surgery in the case of limited involved axillary lymph nodes

“…In the manuscript of Gland Surgery , Vernet-Tomás and colleagues are presenting the results of a pilot phase of the Multimodal Targeted Axillary Surgery (MUTAS) trial ( 1 ). All 25 patients with early breast cancer trial had biopsy-proven involvement of axillary lymph nodes and suspicious lymph nodes on axillary ultrasound.…”

“…The result of the SLNB in this situation was not reliably predicting the additional axillary tumor burden with a false negative rate (FNR) of 28%. Neither for the subgroup of patients with non-palpable axillary involvement (FNR 36%) nor for the subgroup of patients with palpable axillary nodes (FNR 21%) a benefit of SLNB in this situation could be demonstrated ( 1 ). In case of an acceptably low FNR this trial could have been hypothesis generating and would have paved the path for clinical trial deescalating axillary surgery by the use of SLNB also in case of upfront surgery and “clinically” involved lymph nodes.…”