Meta-analysis of sentinel lymph node biopsy in breast cancer

Background. Sentinel lymph node biopsy (SLNB) is a minimally invasive way t o diagnose axillary lymph node (ALN) metastases in breast cancer. The most important features are ability to identify the SLN (I.D. rate), how often t he SLN and ALN pathology match (concordance), and how often the SLN is nega tive for cancer when the ALNs are positive (false negative). Technique and patient criteria for SLNB vary among studies. This study performed meta-ana lysis of published studies to determine the I.D., concordance, and false ne gative rate (1) overall and for (2) both blue dye and radiocolloid, (3) the injection method, (3) palpable and nonpalpable ALNs, and (4) invasive and in situ disease. Methods. Inclusion criteria were patients with breast cancer who had SLNB f ollowed by ALN dissection with H&E staining. Meta-analysis was performed us ing analysis of variance with each observation weighted inversely to its va riance. P < 0.05 was considered significant. Results. Eleven studies (n = 912) met the inclusion criteria. Overall, 762 (84%) SLNs were identified, concordance was 747/762 (98%), and 15/296 (5%) were falsely negative. Highest I.D. rates (P < 0.05) were reported with alb umin radiocolloid or dye + radiocolloid (97 and 94%, respectively), with in jection around an intact tumor (96%), with invasive cancer (95%), and in th e clinically negative axilla (96%). Concordance and false negative rates di d not vary. Conclusions. The SLN can be identified in over 97% of patients if certain t echniques and inclusion criteria are used. SLNB reflects the status of the axilla in 97% of cases and has a 5% false negative rate. (C) 1999 Academic Press.