Outcome of axillary staging in early breast cancer: a meta-analysis

Axillary lymph node dissection (ALND) is associated with significant morbidity, whilst sentinel node biopsy (SNB) has the potential to minimize complications in the management of breast cancer. The aim of this study was to systematically appraise the outcome of SNB when compared to ALND. A comprehensive search for published trials examining outcomes after SNB for breast cancer was performed using medline and cross-referencing available data. Each study was reviewed and data extracted. Primary outcomes were nodal positivity and surgery-related morbidity. A total of 9,608 patients were identified from trials comparing ALND and SNB. The overall rate of axillary lymph node positivity for those with no clinically palpable nodes was 28.8% for ALND and 27.6% for SNB (OR = 1.00, 95% CI = 0.86-1.17, P = 0.956), though there was a trend for superior detection of metastatic disease with SNB when this was compared with ALND alone (OR = 1.22, 95% CI = 0.95-1.57, P = 0.122). Patients who undergo SNB are significantly less likely to suffer post-operative morbidity relative to ALND: risk of infection (OR = 0.58, 95% CI = 0.42-0.80, P = 0.0011), seroma (OR = 0.40, 95% CI = 0.31-0.51, P = 0.0071), arm swelling (OR = 0.30, 95% CI = 0.14-0.66, P = 0.0028) and numbness (OR = 0.25, 95% CI = 0.1-0.59, P = 0.0018). SNB is at least equivalent to ALND in detecting metastatic disease in the axilla. SNB is the optimum approach in terms of morbidity for the assessment of axillary metastasis in clinically node negative breast cancer.