Patterns of failure in women who have residual nodal disease after neoadjuvant chemotherapy for breast cancer according to extent of lymph node surgery

Abstract Purpose Optimal surgical management of limited axillary nodal disease following neoadjuvant chemotherapy (NAC) for breast cancer (BC) is evolving. Concerns exist with respect to leaving residual disease in the axilla when omitting axillary lymph node dissection (ALND) in this setting. We sought to determine whether extent of nodal surgery altered patterns of failure and patient outcomes. Methods We identified 70 patients with BC who were confirmed cN0 after NAC yet had residual nodal disease (ypN1) on SLNB. Twenty-eight patients underwent SLNB alone and 42 underwent SLNB+cALND in a non-randomized fashion. Most patients (n=65) underwent adjuvant RNI. Detailed patterns of failure data were obtained for each patient. Results Median follow-up was 43.5 months. There were 30 recurrences (43%). Of these, 5 were isolated locoregional failures and 24 were distant failures. There were no significant differences in local (p=0.13), regional (p=0.62), or distant (p=0.47) failure between patients who underwent SLNB alone versus SLNB+cALND. Seventeen (24%) patients died. OS was similar in both groups with median OS not reached for those who underwent SLNB and 109 months for those who underwent SLNB+cALND (p=0.45). Conclusions There were no differences in patterns of recurrence among patients with 1-3 involved lymph nodes after NAC who underwent SLNB alone versus SLNB+cALND in the setting of RNI. We await the results of ongoing, prospective clinical trials to confirm the relative merits of RNI in lieu of cALND in these patients.