Is optimal timing of sentinel lymph node biopsy before neoadjuvant chemotherapy in patients with breast cancer? A literature review

BackgroundTwenty five percent of women with breast cancer who undergo preoperative chemotherapy do not have axillary metastases. These patients need to withstand sentinel lymph node biopsy (SLNB). The optimal timing of SLNB in patients with neoadjuvant chemotherapy has not yet been defined.MethodsWe systematically reviewed the literature for studies concerning the efficacy of sentinel lymph node biopsy before neoadjeuvant chemotherapy. A literature search was performed for the years 1993 through 2011 using the databases MEDLINE and EMBASE. Data that assessed the reliability of sentinel lymph node biopsy before chemotherapy were collected.ResultsWe identified 10 high-quality studies from 387 papers, which are analyzed further in this review. The identification rates reported ranged from 97% to 100%. The sensitivities of sentinel lymph node biopsy were 100%, and the false negative rates were 0%. Use an isotope combined with blue dye was associated with a higher probability of identification than that of using an isotope or blue dye alone (99.5% vs 98.5%). Only two studies compared data based on different timing for the sentinel lymph node biopsy. They achieved a lower false negative rate (0% vs 15.8%) and higher success rate (100% vs 81%) in patients with sentinel lymph node biopsy prior to neoadjuvant chemotherapy.ConclusionSentinel lymph node biopsy prior to chemotherapy potentially gives a more accurate evaluation of axillary status, because it is unaffected by any previous therapeutic intervention.