Stage migration with sentinel node biopsy in breast cancer

Background: Axillary staging provides the single most important piece of prognostic information in breast cancer patients. This retrospective study was performed to document the phenomenon of stage migration. Methods: Of 392 patients, 5 (1%) failed identification of sentinel lymph nodes (SLNs) and therefore underwent axillary lymph node dissection (ALND). Four patients (80%) had metastatic lymph nodes, 302 (77%) patients had negative SLNs, 47 (15%) underwent ALND, 85 (22%) had positive SLNs, 11 (13%) received adjuvant radiation treatment to the axilla, and 74 (87%) underwent completion ALND. Results: The median (quartiles) follow-up period was 29 months (19-46 mo). Twenty of 392 (5%) patients had disease relapse; 2 of which were local (.5%) and the rest were systemic. Earlier relapse was related significantly to lymph node status, tumor grade, and tumor size. SLN-negative patients who did not receive ALND had a relapse rate of 2.3% (6 of 256) compared with 0% in those who were truly negative based on confirmatory ALND. SLN-positive patients who did not receive ALND had a 9% (1 of 11) relapse rate. Discussion: The stage-matched pattern of relapse between SLN biopsy and ALND patients revealed lower relapse rates in SLN biopsy-staged patients, documenting the stage migration phenomenon.