Defining the optimal surgeon experience for breast cancer sentinel lymph node biopsy: A model for implementation of new surgical techniques

Objective To determine the optimal experience required to minimize the fals e-negative rate of sentinel lymph node (SLN) biopsy for breast cancer. Summary Background Data Before abandoning routine axillary dissection in fa vor of SLN biopsy for breast cancer, each surgeon and institution must docu ment acceptable SLN identification and false-negative rates. Although some studies have examined the impact of individual surgeon experience on the SL N identification rate, minimal data exist to determine the optimal experien ce required to minimize the more crucial false-negative rate. Methods Analysis was performed of a large prospective multiinstitutional st udy involving 226 surgeons. SLN biopsy was performed using blue dye, radioa ctive colloid, or both. SLN biopsy was performed with completion axillary L N dissection in all patients. The impact of surgeon experience on the SLN i dentification and false-negative rates was examined. Logistic regression an alysis was performed to evaluate independent factors in addition to surgeon experience associated with these outcomes. Results A total of 2,148 patients were enrolled in the study. Improvement i n the SLN identification and false-negative rates was found after 20 cases had been performed. Multivariate analysis revealed that patient age, nonpal pable tumors, and injection of blue dye alone for SLN biopsy were independe ntly associated with decreased SLN identification rates, whereas upper oute r quadrant tumor location was the only factor associated with an increased false-negative rate. Conclusions Surgeons should perform at least 20 SLN cases with acceptable r esults before abandoning routine axillary dissection. This study provides a model for surgeon training and experience that may be applicable to the im plementation of other new surgical technologies.