A comparison of rates of lymph node metastases between patients undergoing sentinel and axillary lymphadenectomy

Background: Recommendations regarding credentialing for sentinel lymphadenectomy in the staging of breast cancer emphasize the need for a trial period during which novice surgeons remove both the sentinel lymph node and the axillary packet, to demonstrate acceptably low rates of both operative failure and inaccuracy. Methods: We initiated sentinel lymph node mapping in our institution without planned axillary dissection. To establish our ability to accurately stage patients using sentinel lymphadenectomy, we compared 225 patients who underwent that procedure and 343 patients previously staged with axillary lymph node dissection. Results: No differences in node positivity were found between the two groups. Among sentinel lymphadenectomy patients, no differences were found between patients in the first and second half of the institutional experience. Conclusions: We question the need for a trial period of planned axillary node dissection with sentinel lymph node mapping, and review the evidence from other investigators regarding its necessity.