Toremifene has been shown to have comparable efficacy against metastatic breast cancer as Tamoxifen. As there is evidence that cross-resistance exists between toremifene and tamoxifen, it is unlikely that toremifene will be effective as a second-line agent after tamoxifen treatment failure. Rather, toremi-fene will most likely be an alternative to tamoxifen.

The most common adverse reactions (AR) seen in the clinical trials include nausea, vomiting and dizziness. Some of the other AR are peripheral edema, vaginal discharge / bleeding, hot flushes, sweating, and hypercalcemia.

At this time, there are minimal clinical data involving long-term toremifene therapy, so the risk for causing endometrial cancer as well as its effects on frequency of cardiac events and bone mineral density are still unclear. Although there is currently no established recommendation of the optimal dose of toremifene clinical studies showed a daily dose of 60 mg to be effective and safe.

Buzdnr AU, Hortobagyi GN. Tamoxifen and toremifene in breast cancer:, comparison of safety and efficacy. Journal of Clinical Oncology 16:348-353, 1998.

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