The recent data from the ATLAS study show that women who had Tamoxifen for at least ten years as an adjuvant treatment, following surgery for hormone-sensitive breast cancer, seem to have a better outcome than those who had Tamoxifen for five years. This is the first study to show that ten years of Tamoxifen is superior to five years. This is a relatively large study involving approximately 7000 women with a longer follow-up than previous studies. Therefore, its result should be considered as more definitive and should have an impact on current clinical practice.
In my opinion, patients who have very favourable prognostic features for their hormone-sensitive breast cancer, such as: small size, grade 1, node negative, probably can take Tamoxifen for five years only. However, those who had more aggressive hormone-sensitive breast cancer, i.e. larger than 2cm, grade 3, node positive etc, should consider taking Tamoxifen for ten years, in order to improve their clinical outcome (by 25/30%). In post-menopausal women Tamoxifen treatment can be switched to an aromatase inhibitor for an extended period so that they will receive at least ten years of endocrine therapy. Whilst Tamoxifen has adverse effects, however, these are esily outweighed by the potential benefits especially in women who had a previous hysterectomy.
By Professor Kefah Mokbel
