Outcome following sentinel lymph node biopsy-guided decisions in breast cancer patients with conversion from positive to negative axillary lymph nodes after neoadjuvant chemotherapy

Many breast cancer patients with positive axillary lymph nodes achieve complete node remission after neoadjuvant chemotherapy. The usefulness of sentinel lymph node biopsy in this situation is uncertain. This study evaluated the outcomes of sentinel biopsy-guided decisions in patients who had conversion of axillary nodes from clinically positive to negative following neoadjuvant chemotherapy. We reviewed the records of 1247 patients from five hospitals in Korea who had breast cancer with clinically axillary lymph node-positive status and negative conversion after neoadjuvant chemotherapy, between 2005 and 2012. Patients who underwent axillary operations with sentinel biopsy-guided decisions (Group A) were compared with patients who underwent complete axillary lymph node dissection without sentinel lymph node biopsy (Group B). Axillary node recurrence and distant recurrence-free survival were compared. There were 428 cases in Group A and 819 in Group B. Kaplan-Meier analysis showed that recurrence-free survivals were not significantly different between Groups A and B (4-year axillary recurrence-free survival: 97.8 vs. 99.0%; p = 0.148). Multivariate analysis also indicated the two groups had no significant difference in axillary and distant recurrence-free survival. For breast cancer patients who had clinical conversion of axillary lymph nodes from positive to negative following neoadjuvant chemotherapy, sentinel biopsy-guided axillary surgery, and axillary lymph node dissection without sentinel lymph node biopsy had similar rates of recurrence. Thus, sentinel biopsy-guided axillary operation in breast cancer patients who have clinically axillary lymph node positive to negative conversion following neoadjuvant chemotherapy is a useful strategy.