An abbreviation for a chemotherapy combination used to treat breast cancer. It includes the drugs doxorubicin hydrochloride (Adriamycin) and cyclophosphamide, followed by treatment with paclitaxel (Taxol). Also called AC-T and AC-Taxol regimen. OR A chemotherapy regimen consisting of doxorubucin hydrochloride (Adriamycin) and cyclophosphamide, followed by paclitaxel (Taxol), administered on either a dose-dense or sequential schedule and used as an adjuvant treatment for breast cancer.