Conclusion Among patients with limited SLN metastatic breast cancer treated with breast conservation and systemic therapy, the use of SLND alone compared with ALND did not result in inferior survival.
Trial Registration clinicaltrials.gov Identifier: NCT00003855
Axillary lymph node dissection (ALND) has been part of breast cancer surgery since the description of the radical mastectomy.1 ALND reliably identifies nodal metastases and maintains regional control,2,3 but the contribution of local therapy to breast cancer survival is controversial.4,5 The Early Breast Cancer Trialists' Collaborative Group synthesized findings from 78 randomized controlled trials, concluding that local control of breast cancer was associated with improved disease-specific survival.6
ALND, as a means for achieving local disease control, carries an indisputable and often unacceptable risk of complications such as seroma, infection, and lymphedema.7- 9 Sentinel lymph node dissection (SLND) was therefore developed to accurately stage tumor-draining axillary nodes with less morbidity than ALND.10 SLND alone is the accepted management for patients whose sentinel lymph nodes (SLNs) are histologically free of tumor, while ALND remains the standard of care for patients whose SLNs contain metastases.11
Cancer biology is much better understood now than it was when ALND was introduced. Biological factors may affect the predilection of some malignant cells to selectively invade lymph nodes rather than visceral organs, just as certain tumor types metastasize to certain organs and not others.12 Recognition of the complexity of tumor biology has changed cancer treatment, with more liberal use of systemic therapy to treat occult cancer cells wherever they may be in the body. Consequently, the decision to administer systemic therapy is influenced by a variety of patient- and tumor-related factors, with lymph node tumor status influencing13,14 but not necessarily dictating the use of chemotherapy.15- 18 Other factors, such as early cancer detection by screening mammography, have led to earlier intervention in breast cancer, reducing the incidence of nodal metastases and even the number of tumor-involved lymph nodes.19