Micrometastases in Axillary Lymph Nodes in Breast Cancer, Post-neoadjuvant Chemotherapy

Study Overview
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Brief Summary
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This study aims to investigate the significance of minimal residual axillary disease following NAC, with a particular focus on micrometastases (ypNmi), in comparison to pathologic lymph node-negative (ypN0) or macrometastases (ypN+). The investigators will further explore the prognostic implications of SLNmi for the prediction of axillary LN status and survival outcomes.

Detailed Description
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This study aims to investigate the significance of minimal residual axillary disease following NAC, with a particular focus on micrometastases (ypNmi), in comparison to pathologic lymph node-negative (ypN0) or macrometastases (ypN+). The investigators will further explore the prognostic implications of SLNmi for the prediction of axillary LN status and survival outcomes.

Official Title
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Micrometastases in Axillary Lymph Nodes in Breast Cancer, Post-neoadjuvant Chemotherapy

Conditions
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Micrometastases, Neoadjuvant Chemotherapy

Intervention / Treatment
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* Procedure: Sentinel lymph node biopsy, axillary lymph node dissection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Stage II or III primary breast cancer patients Patients who performed neoadjuvant chemotherpay Patients who underwent axillary lymph node dissection with or without sentinel lymph node biopsy Exclusion Criteria: Patients who performed upfront surgery De novo stage IV patients

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Procedure: Sentinel lymph node biopsy, axillary lymph node dissection|SLNB was performed using single or dual tracers. For the single tracer technique, Technetium 99, a radioactive substance, was administered periareolarly prior to surgery, and SLNs were identified intraoperatively via a gamma detection system (Neoprobe®). The dual tracer method employed both an isosulfan blue dye and Technetium 99 concurrently. The choice of SLNB technique was contingent upon the surgeon's discretion. SLNs were categorized as one or multiple, and any LN identified by either or both methods was defined as SLN. LNs resected during SLNB without tracer signal were not classified as SLNs. ALND was characterized by the removal of all LNs in axillary levels I and II. Patients documented to have undergone ALND in surgical records were primarily selected from our registry. Among them, those with fewer than 10 LNs were excluded, based on the assumption that a competent ALND necessitated the removal of 10 or more LNs as defined in previous studies|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recurrence-free survival | locoregional recurrence, distant metastasis, any cause of death | the interval from breast cancer diagnosis to the initial recurrence or death upto 5 years |