Epirubicin Plus Tamoxifen Versus Tamoxifen Alone in Node-Positive Postmenopausal Patients With Breast Cancer: A Randomized Trial of the International Collaborative Cancer Group

Abstract

PURPOSE: To assess whether the addition of epirubicin (EPI) therapy to prolonged treatment with tamoxifen (TAM) improves relapse-free and overall survival in postmenopausal women with node-positive primary breast cancer. PATIENTS AND METHODS: Six hundred four patients entered onto a randomized clinical trial were allocated to receive TAM 20 mg/d for 4 years or TAM 20 mg/d for 4 years plus EPI 50 mg/m2 intravenously on days 1 and 8 every 4 weeks for six cycles. Analysis was performed according to allocated treatment, with all randomized patients included (intention to treat), irrespective of eligibility status. RESULTS: After a median follow-up period of 5.7 years, an improvement in relapse-free survival (RFS) was observed for the TAM and EPI–treated patients, compared with those who received TAM alone. The unadjusted hazard ratio was 0.72 (95% confidence interval, 0.54 to 0.96), with a corresponding reduction in the odds of recurrence of 27.9% (SD, 12.3), which was statistically significant (P = .023). Adjustment for prognostic and/or predictive factors did not materially affect the hazard ratio. No difference was observed in terms of overall survival (reduction in odds of death, 11.9% [SD, 16.3]; P = .46). Combined chemohormonal treatment was associated with a higher incidence of acute side effects but without a clear increase in long-term cardiotoxicity. Twelve nonbreast second malignancies, including five hematologic malignancies (two of which were cases of acute myelogenous leukemia), were observed. CONCLUSION: The data show that combined chemohormonal treatment reduces the risk of relapse in postmenopausal patients with node-positive breast cancer. No evidence was found, however, for an improvement in overall survival. The size of benefit observed for both outcomes was consistent with that reported in the Early Breast Cancer Trialists' Collaborative Group overview. The trial presented here, however, provides the first report of an improvement in RFS associated with the provision of a single cytotoxic drug in addition to prolonged TAM.