Sentinel lymph node biopsy for breast cancer: improvement in results over time

Many modifications in the technique of sentinel lymph node (SLN) biopsy for breast cancer have taken place since it was first introduced. This analysis was undertaken to determine, in a large multi-institutional study, whether SLN biopsy results have improved over time. Patients with clinical stage T1-2, N0 breast cancer were enrolled in this prospective study between August 1997 and February 2002. SLN biopsy was performed using blue dye and/or radioactive colloid along with completion level I/II axillary dissection in all patients. The majority of subjects included in this study represent the surgeons' initial experience with SLN biopsy for breast cancer. Statistical comparison of the SLN identification (ID) rate and false-negative (FN) rate were performed by chi-squared analysis. A total of 3370 subjects from 300 surgeons were enrolled in the study. Collectively the SLN ID rate, as well as the mean number of SLNs removed per patient has improved, while the FN rate has remained fairly constant over time. The improved ID rate may be related to improved technical details, while the FN rate has not changed significantly. This highlights the ongoing need for surgeons to perform backup axillary dissection during their initial learning phase.