Sequencing of chemotherapy and radiation therapy in early-stage breast cancer: updated results of a prospective randomized trial. A phase III randomized study on the sequencing of radiotherapy and chemotherapy in the conservative management of early-stage breast cancer.
The optimal integration of chemotherapy with radiation (RT) for patients with early-stage breast cancer remains uncertain. We present the long-term results of a prospective randomized trial to address this question.
                Two hundred forty-four patients were randomly assigned after conservative breast surgery to receive 12 weeks of cyclophosphamide, doxorubicin, methotrexate, fluorouracil, and prednisone (CAMFP) before RT (CT-first) or after RT (RT-first). Median follow-up for surviving patients was 135 months.
                There were no significant differences between the CT-first and RT-first arms in time to any event, distant metastasis, or death. Sites of first failure were also not significantly different.
                Among breast cancer patients treated with conservative surgery, there is no advantage to giving RT before adjuvant chemotherapy. However, this study does not have enough statistical power to rule out a clinically important survival benefit for either sequence. To compare two different timings of radiation treatment in patients with breast cancer who underwent conservative surgery and were candidates to receive adjuvant cyclophosphamide, methotrexate, and fluorouracil (CMF) chemotherapy.
                A total of 206 patients who had quadrantectomy and axillary dissection for breast cancer and were planned to receive adjuvant CMF chemotherapy were randomized to concurrent or sequential radiotherapy. Radiotherapy was delivered only to the whole breast through tangential fields to a dose of 50 Gy in 20 fractions over 4 weeks, followed by an electron boost of 10-15 Gy in 4-6 fractions to the tumor bed.
                No differences in 5-year breast recurrence-free, metastasis-free, disease-free, and overall survival were observed in the two treatment groups. All patients completed the planned radiotherapy. No evidence of an increased risk of toxicity was observed between the two arms. No difference in radiotherapy and in the chemotherapy dose intensity was observed in the two groups.
                In patients with negative surgical margins receiving adjuvant chemotherapy, radiotherapy can be delayed to up to 7 months. Concurrent administration of CMF chemotherapy and radiotherapy is safe and might be reserved for patients at high risk of local recurrence, such as those with positive surgical margins or larger tumor diameters.
The data included in this review, from three well-conducted randomised trials, suggest that different methods of sequencing CT and RT do not appear to have a major effect on recurrence or survival for women with breast cancer if RT is commenced within seven months after surgery.