We hypothesize that 6 cycles of TC versus 6 cycles of TAC will have similar efficacy in the treatment of early stage HER2-negative breast cancer and that TC will have less toxicity. If this hypothesis were upheld and the anthracycline doxorubicin could be eliminated from the regimen while obtaining similar efficacy in this population of patients, it would not only be an important advance in the understanding of the biology of cancer, but it would also be of significant clinical benefit to women with breast cancer.