Factors that determine whether a patient receives completion axillary lymph node dissection after a positive sentinel lymph node biopsy for breast cancer in British Columbia.

Background: Completion axillary lymph node dissection (CALND) is recommended in the setting of positive sentinel lymph node biopsy (SLNB) but is associated with a higher rate of postoperative complications. In this study, the characteristics and outcomes of patients who did and did not have CALND are compared.

Methods: We identified all patients with breast cancer with positive sentinel lymph nodes (SLNs) who did not have concurrent CALND from 2003 to 2006 using a prospectively collected database (British Columbia Cancer Breast Outcomes database) and retrospective chart review. Patient and tumour characteristics were compared between those who received CALND and those who did not.

Results: Among 185 patients with positive SLNs identified by SLNB, 90 had a CALND and 95 had no further surgical therapy. Patients who did not receive CALND had more sentinel nodes removed (p < 0.001), a lower percentage of positive SLNs (p < 0.001) and lower pathologic N stage (p = 0.044) than those who did receive CALND. The size of the breast lesion, size of the largest SLN deposit, estrogen receptor status, grade, lymphovascular invasion, histology and multifocality were not significantly different between groups. Sixty-two percent of women who did not have CALND received radiation to the axilla. Postoperative complication rates (including lymphedema) were higher in the CALND group (21%) compared with the SLNB group (7%). The rates of locoregional recurrence (1% in both groups) and systemic metastases (6% in the CALND group v. 8% in the SLNB group) were similar at 36 months' follow-up.

Conclusion: Compared with women who had CALND, women who did not receive CALND had on average a lower N stage with 3 or more SLNs removed and less than 50% node positivity. Most of these women received radiation therapy to the axilla and had comparable recurrence rates to those who had CALND.