Abstract
Adjuvant tamoxifen has a significant survival benefit in early breast cancer but current data suggest that there is no further benefit beyond 5 years’ treatment. Extended adjuvant therapy with oral letrozole 2.5mg daily following 5 years of tamoxifen in postmenopausal women with hormone receptor-positive breast cancer was shown to significantly reduce the risk of recurrence compared with placebo in the MA-17 trial (predicted 4-year disease-free survival 95% vs 90%). A small but significant overall survival benefit has also emerged in the subset of patients with node-positive disease.
Side effects were generally mild with letrozole, with a slight increase in the incidence of hot flushes, arthralgia, and muscle pain and a reduction in vaginal bleeding. Newly diagnosed osteoporosis was recorded in 8% of patients receiving letrozole compared with 6% of patients receiving placebo (p = 0.003). There was no significant difference in the incidence of cardiovascular events or hypercholesterolemia.
Extended adjuvant therapy with letrozole should now be offered to all but the lowest risk postmenopausal women with hormone receptor-positive disease who are still in remission after 5 years of tamoxifen.
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The author has received research grants and honoraria for lecturing from Novartis, AstraZeneca, and Pfizer.
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Smith, I.E. The Extended Adjuvant Treatment Strategy in Early Breast Cancer. Am J Cancer 5, 1–5 (2006). https://doi.org/10.2165/00024669-200605010-00001
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DOI: https://doi.org/10.2165/00024669-200605010-00001