Completion axillary lymph node dissection not required for regional control in patients with breast cancer who have micrometastases in a sentinel node.

HYPOTHESIS Completion axillary lymph node dissection (ALND) is not required for regional control in patients with metastases in the sentinel lymph node (SLN). DESIGN Prospective cohort study. SETTING Urban teaching hospital. PATIENTS Fifty patients with breast cancer who underwent breast-conserving surgery, had an SLN positive for metastasis, and did not undergo completion ALND. INTERVENTIONS Breast-conserving surgery with SLN biopsy, breast irradiation, and systemic therapy. MAIN OUTCOME MEASURES Locoregional and distant recurrence and survival. RESULTS The mean patient age was 57 years (range, 29-83 years). The mean tumor size was 1.9 cm (range, 0.4-5 cm). The mean number of positive nodes was 1.3 (median, 1; range, 1-2). Fourteen patients (30%) had macrometastases (>2 mm), and 33 patients (71%) had micrometastases. The mean duration of follow-up was 82 months (median, 79 months; range, 6-142 months). One patient with an SLN micrometastasis (1 of 33; 3%) and 1 patient with an SLN macrometastasis (1 of 14; 7%) developed an axillary recurrence with distant metastasis at 84 months and 28 months, respectively. There was 1 death (2%) not related to breast cancer. CONCLUSIONS Patients with SLN metastases who do not undergo ALND have a low incidence of regional recurrence. Axillary lymph node dissection is not necessary for regional control in patients with micrometastatic disease.