Meta-analysis of sentinel lymph node biopsy after preoperative chemotherapy in patients with breast cancer

Background: Women with breast cancer are more frequently being treated with preoperative neoadjuvant chemotherapy. The reliability of sentinel lymph node biopsy (SLNB) following chemotherapy has not been determined. This was a meta-analysis of studies that examined the results of SLNB after preoperative chemotherapy. Methods: Included articles had to meet two criteria. First, patients had to have had operable breast cancer and to have undergone SLNB after preoperative chemotherapy and, second, patients had to have undergone subsequent axillary lymph node dissection. Meta-analyses were performed in which Bayesian hierarchical models were created to estimate the identification rate (IR) and sensitivity of SLNB in this setting. Results: Twenty-one studies were identified that included a total of 1273 patients. The IRs reported ranged from 72 to 100 per cent, with a pooled estimate of 90 per cent. The sensitivity of SLNB ranged from 67 to 100 per cent, with a pooled estimate of 88 (95 per cent confidence interval 85 to 90) per cent. Meta-analyses performed using Bayesian modelling resulted in (posterior) estimates for IR and sensitivity of 91 (95 per cent credible interval 88 to 94) and 88 (95 per cent credible interval 84 to 91) per cent respectively. Conclusion: SLNB is a reliable tool for planning treatment after preoperative chemotherapy.