Safety and efficacy results of a randomized trial comparing adjuvant toremifene and tamoxifen in postmenopausal patients with node-positive breast cancer

Purpose: In this multicenter trial, toremifene 40 mg/d was compared with ta moxifen 20 mg/d, both given orally for 3 years to postmenopausal, axillary node-positive women after breast surgery. Patients and Methods: The first 899 patients (toremifene, n = 459; tamoxife n, n = 440) of the total of 1.480 patients accrued to the trial were includ ed in this scheduled safety analysis. The mean follow-up time was 3.4 years . Results: The two treatment groups were well balanced with respect to patien t and disease characteristics. The subjective side-effect profile wets simi lar in both treatment groups. Slightly more vascular complications (deep ve in thromboses, cerebrovascular events, and pulmonary embolisms) were seen a mong tamoxifen-treated patients (5.9%) as compared with toremifene-treated patients (3.5%) (P = .11), whereas bone fractures (P = .09) and vaginal leu korrhea (P = .05) were more common in the toremifene group. The number of s ubsequent second cancers wets similar. The breast cancer recurrence rate wa s 23.1% (n = 106) in the toremifene group and 26.1% (n = 115) in the tamoxi fen group (P = .31). When only patients with estrogen receptor (ER)-positiv e cancer were considered (n = 556), the risk for breast cancer recurrence w as nonsignificantly lower among the toremifene-treated women, with a hazard s ratio of 0.74 (90% confidence interval, 0.52 to 1.04; P = .14). The mean time to breast cancer recurrence and overall survival were similar in both groups. Conclusion: The side-effect profile of toremifene resembles that of tamoxif en. The efficacy of toremifene seems to be no less than that of tamoxifen. The trend for fewer breast cancer recurrences in the ER-positive subgroup i s encouraging, (C) 2000 by American Society of Clinical Oncology.