Concurrent chemotherapy and radiation for breast conservation treatment of early-stage breast cancer.

Purpose: The optimal sequencing of chemotherapy and radiation therapy in patients with early-stage breast cancer undergoing breast-conservation treatment remains controversial. The purpose of this study is to evaluate the outcome of patients treated with one specific sequence of concurrent chemoradiation followed by additional chemotherapy.
Methods: Between 1977 and 1992, 210 patients with stage I and II breast cancer underwent lumpectomy and axillary lymph node dissection followed by treatment with concurrent chemotherapy and radiation therapy, followed by further chemotherapy. Chemotherapy consisted of two 28-day cycles of CF (oral cyclophosphamide, 100 mg/m2 day 1 to 14, and intravenous 5-fluorouracil, 600 mg/m2 days 1 and 8) during radiation therapy, followed in general by six cycles of CMF (CF doses as above plus intravenous methotrexate 40 mg/m2 days 1 and 8) after the completion of radiation therapy. Fifty patients also received hormonal therapy, predominantly tamoxifen. One hundred ten patients had clinical T1 lesions, and 100 had T2 lesions. Fifty-three patients were pathologic N0, and 157 patients were pathologic N1 (123 patients had one to three positive nodes, and 34 patients had four or more positive nodes). Median follow-up for node-negative patients (5.2 years) is shorter than for node-positive patients (7.6 years). Therefore, outcome is reported at 5 and 10 years for node-positive patients but only at 5 years for node-negative patients.
Results: For node-positive patients, outcomes at 5 and 10 years, respectively, were 86% and 70% for overall survival, 78% and 67% for no evidence of disease survival, and 82% and 69% for freedom from distant metastases. For node-negative patients, outcomes at 5 years were 94% for overall survival, 94% for no evidence of disease survival, and 94% for freedom from distant metastases. Pathologic nodal status was predictive of outcome after treatment. Local failure in the treated breast was 5% at 5 years and 13% at 10 years for all patients.
Conclusions: Concurrent CF with radiation therapy followed by six cycles of CMF after radiation therapy results in excellent survival, freedom from distant metastases, and local control for both node-negative and node-positive patients. This regimen of concurrent chemotherapy and radiation therapy is one option for sequencing, and it avoids the delays in administration of either modality that are associated with other sequencing regimens.