Results of two randomized trials evaluating adjuvant anthracycline-based chemotherapy in 1 146 patients with early breast cancer

Two randomized trials evaluated the effect of 6 courses of anthracycline- based chemotherapy in early breast cancer. A total of 1 146 patients were included: 311 high- risk node- negative premenopausal patients and 835 high- risk node- negative or node- positive postmenopausal patients. Patients were randomized after surgery to receive either no chemotherapy ( control group) or 6 courses of anthracycline- based chemotherapy ( CT group). Postmenopausal patients received adjuvant tamoxifen for at least two years. Radiotherapy was delivered after completion of chemotherapy in the CT group. The 10-year disease- free survival ( DFS) rates were 60% in the control group and 65% in the CT group ( log- rank test, p = 0.01). The 10- year distant metastasis rates were 28% and 23% ( p = 0.02), and the 10- year local recurrence rates were 12% and 10%, respectively ( p = 0.24). Chemotherapy was significantly less effective in post- menopausal patients with estrogen receptor- positive tumors. Adjuvant anthracyclin- based chemotherapy yielded a significant benefit for DFS by lowering the risk of distant metastases. After up to 10 years of follow- up, deferring radiotherapy after chemotherapy did not compromise local control.