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.
Triple-negative cancers constitute about 15% of breast cancers and are usually of high grade. They occur more frequently in young black and Hispanic women than in other ethnic groups. Patients with triple-negative cancers have a higher risk of BRCA1/2 mutations, and BRCA1/2 genetic testing is recommended for women diagnosed with triple-negative breast cancers before age 60 years. Most breast cancers in women with BRCA1 mutations are triple negative.
Antiestrogen therapies such as anastrozole are not effective in hormone receptor–negative cancers and would not be used in this patient's treatment regimen.
Autologous bone marrow transplantation is not used as adjuvant treatment for breast cancer. Clinical trials on its use in both the adjuvant setting and the metastatic setting showed no improvement in survival compared to treatment with standard therapy and its use in breast cancer has been discontinued.
Therapy with bevacizumab, an anti–vascular endothelial growth factor agent, has not been found to improve disease survival or overall survival when added to adjuvant chemotherapy for patients with triple-negative breast cancers.