Purpose: This study sought to quantify the extent of downstaging after preoperative chemotherapy for stage III breast cancer, to assess the feasibility of breast-conserving therapy (BCT) after preoperative chemotherapy, to determine the effectiveness of this multimodal treatment as measured by disease-free survival (DFS) and overall survival (OS), and to evaluate toxicities.
Patients and methods: Patients were treated with 4 preoperative courses of 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC). They were then evaluated for response to go to mastectomy or BCT. After local therapy, patients with an excellent response were treated with 4 additional cycles of FAC, whereas patients with a moderate response received 4 cycles of MV (methotrexate and vinblastine). A total of 203 patients were registered; 194 patients (96%) underwent surgery after chemotherapy.
Results: The 5-year OS and progression-free survival rates were 89.8% and 81.6%, respectively, for patients with an excellent response to therapy compared with 67.2% and 63.5%, respectively, for patients with a moderate response and 55.3% and 48.8%, respectively, for patients considered nonresponders (P=.0005 for OS; P<.0001 for DFS). Cytopenia, nausea/vomiting, and stomatitis were the most common toxicities. Preoperative chemotherapy with FAC downstaged 88.6% of patients, and BCT was possible in >25%.
Conclusion: Response to preoperative chemotherapy was a prognostic factor in improved long-term survival.