Incidence and Prognostic Significance of Complete Axillary Downstaging After Primary Chemotherapy in Breast Cancer Patients With T1 to T3 Tumors and Cytologically Proven Axillary Metastatic Lymph Nodes

PURPOSE: To determine the incidence and prognostic significance of eradication of cytologically proven axillary lymph node metastases in breast cancer patients treated with primary chemotherapy. PATIENTS AND METHODS: Between January 1985 and December 1994, 152 breast cancer patients with invasive T1 to T3 tumors and axillary metastases cytologically proven by fine-needle sampling underwent primary chemotherapy followed by lumpectomy or mastectomy, level I and II axillary lymph node dissection, and irradiation. We studied pathologic complete responses (pCRs) of axillary nodes and breast tumors, as well as predictors of distant metastases. RESULTS: Thirty-five patients (23%) had axillary pCRs, and 20 patients (13.2%) had pCRs of primary breast tumors. Scarff-Bloom-Richardson grade 3 tumors (P =.04) and a clinical response to chemotherapy > or = 50% (P =.003) were associated with negative axillary status at dissection. An initial tumor size < or = 3 cm (63 patients) was associated with pCR of the primary tumor (P =.02) but not with complete histologic clearance of axillary lymph nodes. The median length of follow-up was 75 months. In the univariate analysis, age greater than 40 years (P =.003), absence of residual nodal disease (P =.01), and pCR of the tumor (P =.05) were associated with better distant disease-free survival. Five-year distant disease-free survival rates were 73.5% +/- 14.9% among patients with no involved nodes at the time of surgery and 48.7% +/- 9.2% among patients with residual nodal disease. In the multivariate Cox regression analysis, parameters associated with poor distant disease-free survival were age < or = 40 years (P =.002), persistence of nodal involvement (P =.03), and S-phase fraction greater than 4% (P =.02). CONCLUSION: Our results suggest that axillary status is a better prognostic factor than response of the primary tumor to primary chemotherapy.