Cytologically proven axillary lymph node metastases are eradicated in patients receiving preoperative chemotherapy with concurrent trastuzumab for HER2-positive breast cancer

BACKGROUND: The axillary pathologic complete response rate (pCR) and the effect of axillary pCR on disease-free survival (DFS) was determined in patients with HER2-positive breast cancer and biopsy-proven axillary lymph node metastases who were receiving concurrent trastuzumab and neoadjuvant chemotherapy. The use of neoadjuvant chemotherapy is reported to result in pCR in the breast and axilla in up to 25% of patients. Patients achieving a pCR have improved DFS and overall survival. To the authors' knowledge, the rate of eradication of biopsy-proven axillary lymph node metastases with trastuzumab-containing neoadjuvant chemotherapy regimens has not been previously reported. METHODS: Records were reviewed of 109 consecutive patients with HER2-positive breast cancer and axillary metastases confirmed by ultrasound-guided fine-needle aspiration biopsy who received trastuzumab-containing neoadjuvant chemotherapy followed by breast surgery with complete axillary lymph node dissection. Survival was evaluated by the Kaplan-Meier method. Clinicopathologic factors and DFS were compared between patients with and without axillary pCR. RESULTS: Eighty-one patients (74%) achieved a pCR in the axilla. Axillary pCR was not associated with age, estrogen receptor status, grade, tumor size, initial N classification, or median number of lymph nodes removed. More patients with an axillary pCR also achieved a pCR in the breast (78% vs 25%; P < .001). At a median follow-up of 29.1 months, DFS was significantly greater in the axillary pCR group (P = .02). CONCLUSIONS: Trastuzumab-containing neoadjuvant chemotherapy appears to be effective in eradicating axillary lymph node metastases in the majority of patients treated. Patients who achieve an axillary pCR are reported to have improved DFS. The success of pCR with concurrent trastuzumab and chemotherapy in eradicating lymph node metastases has implications for surgical management of the axilla in these patients.