Clinical Trial Comparing Letrozole (Femara®) to Placebo Following Tamoxifen Therapy to Reduce the Risk of Cancer Recurrence Among Post-Menopausal Women Originally Diagnosed with Early-Stage Breast Cancer. The study found that cancer returned much less often in the women taking letrozole compared to those on placebo.

The participants in the study of post-menopausal women who had been treated for early-stage breast cancer and who were given letrozole or a placebo after completing five years of tamoxifen therapy were followed for an average of 2.4 years and for as long as five years. In total, 132 women taking the placebo had their disease recur compared to 75 on letrozole. Overall, letrozole reduced the risk of recurrence by 43 percent so that, after an average of four years, 13 percent of the women on the placebo, but only 7 percent those on letrozole had recurred. These reductions included fewer recurrences in the breast where the original cancer occurred, in the opposite breast and in internal organs.

The results of this study appeared in the advance on-line edition of the New England Journal of Medicine on Oct. 9, 2003.

This study was the first to use an aromatase inhibitor during years five through 10 after a breast cancer diagnosis in patients who had completed five years of treatment with tamoxifen.

** 30 women participated in this study through our MCRC-CCOP network of community hospitals.