Randomized Double-Blind Trial In Postmenopausal Women With Primary Breast Cancer Who Have Received Adjuvant Tamoxifen For 2-3 Years, Comparing Subsequent Adjuvant Exemestane Treatment With Further Tamoxifen

To compare the sequential administration of exemestane with administration of further tamoxifen until 5 years in postmenopausal women with operable breast cancer who have already received 2-3 years of adjuvant tamoxifen, in terms of disease-free survival (DFS), overall survival (OS), incidence of contralateral breast cancer and long-term tolerability.