Sentinel Node Biopsy After Neoadjuvant Chemotherapy In Breast Cancer Patients With Initial Clinical Positive Node:Systematic Review And Meta-analysis

Background:Neoadjuvant chemotherapy (NAC) has been administered increasingly more often to facilitate breast-conserving surgery. Following NAC, axillary lymph node dissection (ALND), which is often associated with substantial morbidity, is usually performed for nodal staging at the time of breast surger. Thus, a less aggressive approach to ALND is desired. Sentinel lymph node biopsy (SLNB) can reduce the morbidity of breast cancer treatment by sparing the patients from ALND. However, although this procedure is the standard method for nodal staging in early-stage breast cancer patients. with increasing experience, more recent and larger studies have reported that the identification rate (IR) and false negative rate (FNR) of SLNB after NAC were comparable to those of standard SLNB. However eligibility for post-neoadjuvant chemotherapy sentinel node mapping among patients with initial clinical node positive status remains under debate. In the present systematic review, we evaluated the identification and false negative rates of sentinel node biopsy in breast cancer patients with and in those without initial clinical node positive status.Methods:PubMed and Cochrane libraries were queried for relevant studies with direct comparison between patients with and those without clinical node positive status. The outcomes of interest were identification and false negative rates in each group. Comparison of the odds ratio and risk difference of sentinel node identification failure or false negative results between the clinical node positive and clinical node negative groups was also examined.Results:Thirteen studies on the evaluation of the false negative rate and15on the evaluation of the identification rate were included in this review. Pooled identification rates for patients with and for those without clinical node positive status were87.4%and87.8%, respectively. The odds ratio and risk difference of identification failure during surgery were1.81and0.05, respectively. Pooled false negative rates for patients with and for those without prior surgical biopsy were15.2%and11.5%, respectively. The odds ratio and risk difference of false negative results were1.38and0.07, respectively. Conclusion:A number of recent studies assessing the feasibility of SLNB after NAC in patients with initial cN+have reported promising results with advantageous IRs and low FNRs. Thus, clinical node status before neoadjuvant chemotherapy may not affect the identification and false negative rates of sentinel lymph node biopsy. Our analysis suggests that sentinel lymph node biopsy could be beneficial in patients with clinical node positive status prior to neoadjuvant chemotherapy. SLNB can be safely performed on patients who are down-staged to cNO from cN+and converted to pathologic complete response after NAC. However, publication bias seems to be a limitation of our review; therefore, more studies need be included in this meta-analysis.