Sentinel node positive breast cancer patients who do not undergo axillary dissection: Are they different?

Background: Little data address outcome in patients with sentinel lymph node (SN) metastases without completion axillary lymph node dissection (CALND). This study was designed to assess locoregional recurrence in patients with positive SNs who did not undergo CALND. Methods: An IRB-approved, retrospective chart review was conducted on breast cancer patients with a positive SN. Follow-up information on outcomes was obtained via mailed questionnaires and chart review. Comparative analyses were performed between patients who did and did not undergo CALND after a positive sentinel lymph node biopsy. Results: From November 1998 to June 2004, 625 breast cancer patients had a positive sentinel lymph node biopsy. One-hundred and eighteen patients with ≤0.2 mm nodal metastases (N0i+) were excluded from the study. Of the remaining 507 patients, 421 underwent CALND and 86 did not. In comparison to patients who had CALND, patients who did not undergo CALND had smaller primary tumors (2 vs 2.6 cm, P = .0007) and were more likely to have a single positive sentinel node (92% vs 77%, P = .002). The metastasis size of the sentinel node was smaller compared to patients who underwent axillary dissection (1.7 vs 6.4 mm, P < .0001). Mean predicted probability of nonsentinel node metastasis in patients who did not undergo CALND was 20% compared to 47% in patients who did (P < .0001). During a median follow-up of 30 months, there were no axillary recurrences. Conclusions: These data confirm that patients who have a positive sentinel node biopsy and do not undergo CALND have a lower risk profile for axillary disease. In this lower risk subset, axillary treatment may not be necessary.