Is sentinel lymph node biopsy recommended for invasive breast carcinoma?

Sentinel Lymph Node Biopsy for Invasive Breast Carcinoma

Sentinel lymph node biopsy is the preferred method of axillary lymph node staging for invasive breast carcinoma when performed by an experienced sentinel node team. 1

Rationale and Benefits

• Sentinel lymph node biopsy (SLNB) has replaced routine level I and II axillary lymph node dissection (ALND) as the standard approach for axillary staging in clinically node-negative invasive breast cancer 1
• Randomized clinical trials have demonstrated decreased arm and shoulder morbidity (including pain, lymphedema, and sensory loss) with SLNB compared to standard axillary node dissection 1
• SLNB shows no significant differences in effectiveness compared to level I and II dissection for determining the presence or absence of axillary node metastases 1

Patient Selection Criteria

• SLNB is indicated for patients with clinically negative axillary lymph nodes or those with negative core or fine needle aspiration (FNA) biopsy of any clinically suspicious axillary lymph nodes 1
• The procedure is appropriate for clinical stage I or II invasive breast cancer 1
• Patients should have access to an experienced sentinel lymph node team, which includes a surgeon, radiologists, nuclear medicine physician, pathologist, and prior discussion with medical and radiation oncologists 1

Technical Considerations

• Sentinel lymph node mapping injections may be peritumoral, subareolar, or subdermal 1
• Only peritumoral injections map to the internal mammary lymph nodes 1
• Sentinel node involvement is defined by multilevel node sectioning with hematoxylin and eosin (H&E) staining 1
• Cytokeratin immunohistochemistry should be used only for equivocal cases on H&E staining, not as routine practice 1

Management Based on SLNB Results

• If the sentinel lymph node cannot be identified or is positive for metastasis, a formal axillary lymph node dissection should be performed (category 2A) or axillary irradiation administered (category 2B) 1
• Data from a randomized trial suggest that complete axillary lymph node dissection in women with clinically node-negative T1-T2 tumors with fewer than 3 involved sentinel lymph nodes who are undergoing breast-conserving surgery and whole breast radiation results in more morbidity without improvement in locoregional recurrence rates or overall survival 1

Special Considerations

• For patients undergoing preoperative chemotherapy with clinically negative axillary nodes, prechemotherapy sentinel lymph node biopsy is the preferred option for surgical axillary staging 1
• If the sentinel lymph node is histologically negative in these patients, omission of axillary dissection may be considered at the time of definitive surgical therapy 1
• If the sentinel lymph node is histologically positive, then level I and II axillary dissection should be performed at the time of definitive surgical therapy 1

Potential Pitfalls and Caveats

• ALND remains indicated in women found to have axillary lymph node involvement on sentinel lymph node excision 1
• Women who do not undergo axillary dissection or axillary lymph node irradiation are at increased risk for ipsilateral lymph node recurrence 1
• In the absence of definitive data showing superior survival with ALND or SLNB, these procedures may be considered optional in patients with particularly favorable tumors, those for whom adjuvant systemic therapy selection won't be affected by the results, elderly patients, or those with serious comorbid conditions 1

By following these evidence-based recommendations for sentinel lymph node biopsy in invasive breast carcinoma, clinicians can provide optimal axillary staging while minimizing morbidity associated with more extensive axillary surgery.