What is the Burden of Axillary Disease after Neoadjuvant Therapy in Women with Locally Advanced Breast Cancer?

Background: The burden of axillary disease in patients with locally advanced breast cancer (labc) after neoadjuvant therapy (nat) has not been extensively described in a large modern cohort. Here, we describe the extent of nodal metastases after nat in patients with labc. Methods: All patients with labc treated at a single institution during 2002–2007 were identified. Demographic, radiologic, and pathologic variables were extracted. To assess the extent of lymph node metastases after nat, patients were separated into two groups: those with and without clinical or radiologic evidence of lymph node metastases before nat. Axillary lymph nodes retrieved at surgery that had no evidence of metastases after hematoxylin and eosin (h&e) staining underwent further pathology evaluation. Results: Of the 116 patients identified, 115 were female (median age: 48.5). Before nat, 26 patients were clinically and radiologically node-negative; of those 26, 14 were histologically negative on final pathology. After serial sectioning and immunohistochemistry, 9 of 26 (35%) were node-negative. Of the 90 patients who had clinical or radiologic evidence of lymph node metastases before nat, 23 (26%) had no evidence of lymph node metastases on h&e staining. After serial sectioning and immunohistochemistry, 19 (21%) had no further axillary lymph node metastases. Overall, 76% of patients had pathology evidence of lymph node metastases after nat. Conclusions: Most patients with labc have axillary metastases after nat. Our findings support axillary lymph node dissection and locoregional radiation in most patients with labc after nat.