OUTLINE: This is a randomized, multicenter study. Patients are stratified according to nodal status (negative vs 1-3 vs 4 or more), age (50 and under vs over 50), estrogen receptor status (negative vs weakly positive vs positive), concurrent radiotherapy (no vs yes), HER2 status (3+ overexpression vs other vs not measured), and country. Patients are randomized to 1 of 2 treatment arms.