Sentinel lymphadenectomy for breast cancer in a community managed care setting

To evaluate the feasibility, accuracy, and reproducibility of intraoperative lymphatic mapping and sentinel lymphadenectomy (IOLM/SL) in the staging of breast cancer patients in a community managed care setting.

One hundred forty-five patients with primary breast cancer were prospectively studied over a 26-month period. They underwent vital dye injection at their primary breast cancer site. Lymphatic channels were traced to the sentinel lymph node, which was excised, serially sectioned, and examined. A level I and II axillary lymph node dissection and definitive breast surgery were then performed.

Sentinel nodes were identified in 103 of 145 procedures (71.0%). Sentinel and nonsentinel lymph nodes were concordant in 100 of 103 cases (97.1%). Three patients (9.7%) had falsely negative sentinel nodes; there were none in the last 80 patients. Of 28 positive sentinel nodes, 12 (42.9%) represented the only tumor-containing node within the axilla. Sentinel nodes were significantly more likely to contain tumor than nonsentinel nodes (33/50, 66.0% vs 54/467, 11.6%, P < 0.0001). IOLM/SL identified more micrometastases (< 2 mm) than standard axillary lymph node dissection (13/33, 39.6% vs 4/177, 2.2%, P < 0.001). Nine of 42 patients (21.4%) whose sentinel node could not be identified had five or more nodal metastases. Two of six patients with presumed Tis primaries had nodal metastases.

IOLM/SL accurately identifies the sentinel lymph node(s) most likely to contain metastatic disease. A procedural learning curve was present. An unsuccessful IOLM/SL was a risk factor for considerable nodal metastases. IOLM/SL with a tumor-free sentinel node may obviate a formal axillary lymph node dissection. The technique was feasible, economical, and reproducible within the context of a community managed care facility, while not placing exacting demands on operating room, pathology, or nuclear medicine personnel.