Concurrent cyclophosphamide, methotrexate, and 5-fluorouracil chemotherapy and radiotherapy for early breast carcinoma.

PURPOSE: The optimal sequencing of adjuvant chemotherapy (CT) and radiation therapy (RT) in patients with early-stage breast cancer remains unclear.

PATIENTS AND METHODS: We retrospectively compared 485 patients treated with conservative breast surgery and postoperative whole-breast RT and six courses of CMF (cyclophosphamide 600 mg/m(2), methotrexate 40 mg/m(2), and 5-fluorouracil 600 mg/m(2)) with 300 patients who received postoperative CMF only and with 509 patients treated with postoperative whole-breast RT only. The mean radiation dose delivered was 50 Gy (range, 46-52 Gy) with standard fractionation. The boost dose was 6-16 Gy according to resection margins and at the discretion of the radiation oncologist. Acute and late RT toxicity were scored using respectively the Radiation Therapy Oncology Group and the Late Effects in Normal Tissues Subjective, Objective, Management and Analytic scale.

RESULTS: A slightly higher Grade 2 acute skin toxicity was recorded in the concurrent group (21.2% vs. 11.2% of the RT only group, p < 0.0001). RT was interrupted more frequently in the CMF/RT group respective to the RT group (8.5% vs. 4.1%; p = 0.006). There was no difference in late toxicity between the two groups. All patients in the concurrent group successfully received the planned dose of RT and CT. Local recurrence rate was 7.6% in CT/RT group and 9.8% in RT group; this difference was not statistically significant at univariate analysis (log-rank test p = 0.98). However, at multivariate analysis adjusted also for pathological tumor, pathological nodes, and age, the CT/RT group showed a statistically lower rate of local recurrence (p = 0.04).

CONCLUSIONS: Whole-breast RT and concurrent CMF are a safe adjuvant treatment in terms of toxicity.