Anthracycline-based chemotherapy is the most appropriate treatment. Although this patient has a stage I cancer (measuring 2 cm or less and lymph node negative), it is a high-grade, triple-negative tumor (negative for estrogen receptor, progesterone receptor, and HER2 amplification), and she is at high risk for systemic recurrence. In patients with triple-negative cancers that are 0.6 cm or greater in size, adjuvant chemotherapy, typically anthracycline-based chemotherapy, is recommended if there are no medical contraindications. Chemotherapy is the mainstay of treatment for triple-negative breast cancers, both when used as adjuvant therapy and when used for more advanced cancers. Based on retrospective analysis, adding a taxane agent to adjuvant anthracycline-based chemotherapy is of greater benefit in patients with hormone receptor–negative cancers than in patients with hormone receptor–positive cancers.