Sentinel node skills verification and surgeon performance - Data from a multicenter clinical trial for early-stage breast cancer

Objective: Marked variations in sentinel lymph node dissection (SLND) technique have been identified, and definitive qualifications for SLND performance remain controversial. Based on previous reports and expert opinion, we predicted that 20 to 30 cases of SLND with axillary lymph node dissection (ALND) would enable surgeons to identify sentinel lymph nodes (SLN). Summary Background Data: In 1999, the American College of Surgeons Oncology Group initiated a prospective trial, Z0010, to evaluate micrometastatic disease in the SLN and bone marrow of women with early-stage breast cancer. Eligible patients included women with biopsy-proven T1/T2 breast cancer and clinically negative lymph nodes who were candidates for lumpectomy and SLND. Methods: Participating surgeons were required to document 20 to 30 SLNDs followed by immediate ALND with failure rates less than 15%. Prior fellowship or residency training in SLND provided exemption from skill requirements. Data for 5237 subjects and 198 surgeons were available for analysis. Results: Surgeons from academic (48.4%), community (28.6%), or teaching-affiliated (19.8%) institutions qualified with 30 SLND + ALND cases (64.6%), 20 cases (22.2%), or exemption (13.1%). Participants used blue dye + radiocolloid in 79.4%, blue dye alone in 14.8%, and radiocolloid alone in 5.7% of cases, achieving a 98.7% SLN identification rate. Patient factors associated with increased SLND failure included increased body mass index and age, whereas tumor location, stage, and histology, presence of nodal metastases, and number of positive nodes were not. Surgeon accrual of fewer than 50 patients was associated with increased SLND failure; however, SLND technique, specific skill qualification, and institution type were not. Conclusions: Using a standard skill requirement, surgeons from a variety of institutions achieved an acceptably low SLND failure rate in the setting of a large multicenter trial, validating the incorporation of SLND into clinical practice.