6: Impact of clipped node as a sentinel lymph node on axillary staging following neoadjuvant chemotherapy in clinically node-positive breast cancer

Friday, March 22, 2024

11:22am – 11:32am ET

Location: Georgia Ballroom

Abstract Presenter(s)

Alexandra Moore, MD

Fellow Physician
MD Anderson Cancer Center
Houston, Texas, United States

Submitter(s)

Alexandra Moore, MD

Fellow Physician
MD Anderson Cancer Center
Houston, Texas, United States

Author(s)

Alexandra Moore, MD

Fellow Physician
MD Anderson Cancer Center
Houston, Texas, United States
Abigail S. Caudle, MD, MS, FACS

Associate Professor, Department of Breast Surgical Oncology
MD Anderson Cancer Center
Houston, Texas, United States
SS

Susie X. Sun, MD

Assistant Professor
Department of Breast Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA, United States
Henry M. Kuerer, MD, PhD

Professor
Department of Breast Surgical Oncology, MD Anderson Cancer Center, Houston, TX, USA
Houston, Texas, United States
Kelly K. Hunt, MD (she/her/hers)

Professor & Chair
Department of Breast Surgical Oncology, MD Anderson Cancer Center, Houston, TX, USA
Houston, Texas, United States
SK

Savitri Krishnamurthy, MD

Professor, Department of Pathology, Division of Pathology and Laboratory Medicine
MD Anderson Cancer Center
Houston, Texas, United States
WY

Wei Yang, MBBS, FRCR

Professor and Chair, Department of Diagnostic Radiology
MD Anderson Cancer Center, United States
Benjamin D. Smith, MD

Professor
Department of Breast Radiation Oncology, MD Anderson Cancer Center, Houston, TX, USA
Houston, Texas, United States
VV

Vicente Valero, MD, FACP

Professor and Deputy Chairman, Department of Breast Medical Oncology
MD Anderson Cancer Center, United States
Mediget Teshome, MD (she/her/hers)

Associate Professor
UCLA
Los Angeles, California, United States

Disclosure(s):

Alexandra Moore, MD: No financial relationships to disclose

Kelly K. Hunt, MD: Armada Health: Advisor (Ongoing); AstraZeneca: Consultant (Ongoing), Speaker (Ongoing); Cairn Surgical: Contracted Research (Ongoing); Lumicell: Contracted Research (Ongoing)

Mediget Teshome, MD: Endomagnetics: Other (Terminated, November 6, 2022)

Introduction: Residual disease after neoadjuvant chemotherapy (NCT) is prognostic and informs adjuvant treatment. Targeted axillary dissection (TAD) provides axillary staging after NCT with low false negative rates in cN1 breast cancer facilitating omission of axillary dissection (ALND) in ypN0 disease. TAD technique includes selective excision of the biopsy-proven clipped node and sentinel lymph node (SLN) dissection, given prior studies described the clipped node is not a SLN in ~25% of patients. This study evaluates incidence and factors associated with the clipped node being a non-SLN on TAD.

Methods: Retrospective review of a prospective institutional database was performed to identify cN1 breast cancer patients treated with NCT and TAD from July 2013-June 2023. Patients with planned ALND were excluded. Nodal ultrasound (US) and needle biopsy defined cN1 status. Patient, tumor and treatment characteristics were evaluated and compared based on clipped node status (SLN or non-SLN). Multivariate analysis of factors associated with clipped node as a non-SLN was performed.

Results: 680 patients underwent TAD, and the majority received dual tracer mapping (n=643, 94.6%). In 3 patients (0.4%) no SLN was identified. The clipped node was a SLN in 610 patients (90%) and non-SLN in 70 (10%). When the clipped node was a non-SLN, 42 (60%) were positive for metastasis. In 22 of the 42 patients (52%), the clipped node was positive, was a non-SLN and all SLNs were negative for metastasis. There were no differences in demographic, clinical or pathologic factors when comparing clipped node SLN status (Table 1). The clipped node as a non-SLN cohort had a higher proportion of patients with > 3 suspicious nodes on US at presentation (p=0.003), fewer SLNs excised (mean 2.2 vs 3.5, p=< 0.001) and lower proportion with a positive SLN (p=< 0.001). On multivariate analysis, >3 suspicious nodes on US (OR 3.0, p=0.001) and tumor size at diagnosis (OR 0.9, p=0.02) were significantly associated with the clipped node as a non-SLN.

Conclusions: When the clipped node was a non-SLN and positive, half of the time it was the only positive node on TAD. In these patients, the clipped node is the only identifiable residual disease in the axilla and not detected by SLN dissection. Given implications for adjuvant multidisciplinary decision making, selective excision of the clipped node is recommended to facilitate precise identification of residual nodal disease after NCT.

Learning Objectives:

Describe the TAD technique and understand its role in surgical staging of the axilla.
Understand the utility of selective excision of the clipped biopsy-proven axillary node in surgical staging of the axilla.
Identify clinical factors which are associated with the clipped axillary node being a non-SLN.