Prognostic Factors in Patients with Stage II/III Breast Cancer Treated with Adjuvant Extension of Neoadjuvant Chemotherapy: A Retrospective Cohort Study with Ten-Years of Follow-Up Data

PURPOSE: The aim of this retrospective study was to identify the reliable long term prognostic factors in patients with stage II/III breast cancer who were treated with an adjuvant extension of neoadjuvant chemotherapy (NC). METHODS: Women under the age of 70-years, with previously untreated clinical stage II and III breast cancer, were treated with NC, which was comprised of three cycles of FEC (5-FU, epirubicin, and cyclophosphamide every 3 weeks) or MMM (methotrexate, mitoxantrone, and mitomycin-C every 3 weeks) with an adjuvant extension of three cycles of the same regimen. RESULTS: Cumulative 10-years disease-free survival (DFS) was 87.3% for patients with a good response and 55.5% for patients with no response (p=0.032); 92.9% for node negative patients, 75.0% for 1-3 positive nodes, 50.0% for 4-9 positive nodes and no survival for 10 or more positive nodes (p<0.001). Cumulative 10-years overall survival (OS) was 89.1% for patients with good response and 55.5% for patients with no response (p=0.024); 95.2% for node negative patients, 80.0% for 1-3 positive nodes, 50.0% for 4-9 positive nodes and no survival for 10 or more positive nodes (p<0.001). No significant difference was observed in DFS and OS between the FEC and MMM treated groups. CONCLUSION: Based on a review of data with a long follow-up, only the clinical response to NC and the absolute number of metastatic axillary lymph node identified at surgical staging were independent predictors of both DFS and OS in patients with stage II/III breast cancer patients treated with adjuvant extension of NC.