Risk Factors Associated With Sentinel Lymph Node Metastasis in Clinically Node-Negative Breast Cancer

Area of Science:

• Oncology
• Surgical Pathology

Background:

• Sentinel lymph node biopsy (SLNB) is standard for axillary staging in node-negative breast cancer.
• Identifying predictive factors for SLN metastasis can optimize patient selection for SLNB and avoid unnecessary axillary surgery.

Purpose of the Study:

• To identify risk factors for sentinel lymph node (SLN) metastasis in breast cancer patients in Bahrain.
• To evaluate the potential for de-escalating axillary surgery based on predictive factors.

Main Methods:

• Retrospective analysis of 160 clinically node-negative breast cancer patients who underwent SLNB (2016-2022).
• Exclusion criteria included failed SLN localization, bilateral cancers, and treatment for local recurrence.
• Univariate and multivariate analyses were performed to identify predictors of SLN metastasis.

Main Results:

• Tumor grade, lymphovascular invasion (LVI), and tumor size were significant predictors of SLN metastasis in univariate analysis.
• Age was not an independent predictor on multivariate analysis.
• 64.4% of patients had negative SLNB; 21.9% underwent axillary dissection.

Conclusions:

• High tumor grade, LVI, and large tumor size are associated with axillary metastasis after SLNB.
• Lower SLN metastasis incidence in the elderly suggests potential for de-escalating axillary surgery in this group.
• Findings may inform the development of a nomogram for estimating SLN metastasis risk.