Toremifene and tamoxifen have similar efficacy in the treatment of patients with breast cancer: a meta-analysis of randomized trials

A meta-analysis of randomized trials was performed to compare the efficacy of toremifene (TOR) with tamoxifen (TAM) in patients with breast cancer. A total of 4,768 intention-to-treat patients from nine randomized trials were identified, with 2,587 patients in TOR group and 2,181 patients in TAM group. The primary outcomes were objective response rate (ORR), time to progression (TTP), and overall survival (OS). The ORR for TOR group was 26.2 % (303/1,156), whereas the ORR for TAM group was 25.2 % (284/1,128). The pooled RR suggested that the ORR were not statistically different between the two therapeutic groups (RR 1.04, 95 % CI 0.91–1.20, P = 0.57). The median TTP was 6.7 months for the TOR group and 9.7 months for the TAM group. The median OS was 30.1 months for the TOR group and 31.7 months for the TAM group. There were no significant difference in TTP and OS between two therapeutic groups (for TTP: HR 0.91, 95 % CI 0.82–1.00; for OS: HR 1.02, 95 % CI 0.91–1.15). Adverse events were generally similar in two therapeutic groups, but TOR may cause fewer vaginal bleeding (4.0 vs. 6.7 %, P < 0.01), headache (0.2 vs. 3.1 %, P = 0.02) and thromboembolic events (4.7 vs. 7.0 %, P = 0.04). Sensitivity analyses were performed by deleting a single study each time; all the results were not materially altered. In summary, the results of this meta-analysis suggest that TOR and TAM have similar efficacy in the treatment of patients with breast cancer.