Sentinel lymph nodes for breast carcinoma: an update on current practice

Area of Science:

• Oncology
• Surgical Pathology
• Breast Cancer Research

Background:

• Sentinel lymph node (SLN) biopsy is the standard for axillary staging in invasive breast carcinoma with clinically negative lymph nodes (cN0).
• Historically, a positive SLN biopsy mandated axillary lymph node dissection (ALND).
• The ACOSOG Z0011 trial established criteria for safely omitting ALND.

Purpose of the Study:

• To review the established role of SLN biopsy in breast cancer staging.
• To discuss the implications of the ACOSOG Z0011 trial on axillary staging protocols.
• To highlight current best practices for SLN pathological evaluation and ongoing research areas.

Main Methods:

• Review of established clinical guidelines and landmark trial data (ACOSOG Z0011).
• Description of optimal pathological techniques for SLN evaluation, including gross sectioning and H&E staining.
• Discussion of the evolving role of SLN biopsy in the context of neoadjuvant chemotherapy.

Main Results:

• The ACOSOG Z0011 trial demonstrated that women with T1-T2, cN0 breast cancer undergoing breast-conserving surgery and radiotherapy can safely avoid ALND after a positive SLN biopsy.
• Optimal pathological evaluation focuses on detecting macrometastases (>2 mm) using gross sectioning and H&E staining.
• The management of SLN biopsies in patients receiving neoadjuvant chemotherapy remains an area of active clinical investigation.

Conclusions:

• SLN biopsy is crucial for axillary staging in early breast cancer.
• ALND can be safely omitted in select patients based on trial evidence and multidisciplinary treatment.
• Standardized pathological evaluation of SLNs is essential, with ongoing research addressing neoadjuvant chemotherapy scenarios.