ADJUVANT TRIALS OF TOREMIFENE VS TAMOXIFEN - THE EUROPEAN EXPERIENCE

When results from the phase II trials of toremifene (Fareston) and tam oxifen (Nolvadex) in metastatic breast cancer were published, the Finn ish Breast Cancer Group began to plan the first trial of toremifene in an adjuvant setting. This multicenter; randomized trial is comparing toremifene (40 mg/d) to tamoxifen (20 mg/d) in postmenopausal lymph no de-positive breast cancer patients. Treatment duration is 3 years. Abo ut 1,150 of a planned 1,460 patients have been enrolled to date. The I nternational Breast Cancer Study Group is also conducting two adjuvant trials evaluating 5 years of toremifene (60 mg/d) vs tamoxifen (20 mg /d). More than 2,000 patients have been enrolled in these studies to d ate. The efficacy of toremifene is being explored in all of these tria ls. In the Finnish trial, additional protocols are evaluating treatmen t side effects, including the formation of DNA adducts in the endometr ium and leukocytes, certain ocular problems, thromboembolic events, an d subjective side effects. The effects of toremifene on lipid levels a nd bone density ape also being studied. Art interim safety analysis, p erformed in the Finnish study after 500 patients were enrolled (mean f ollow-up, 18 months), skewed no significant differences between toremi fene and tamoxifen in terms of efficacy or side effects. Toremifene se ems to be well tolerated and may have additional positive effects. Ong oing trials will soon reveal how beneficial toremifene is in the adjuv ant setting and whether it is devoid of the adverse effects observed w ith tamoxifen.