Neoadjuvant and Adjuvant Therapies for Breast Cancer.

Breast cancer remains the most common cancer in women in the United States, the second most common cause of cancer death, and the main cause of death in women ages 45 to 55 years. Molecular analyses have shown that breast cancer is divided into several subtypes (luminal A, luminal B, human epidermal growth factor receptor 2 [HER2] enriched, and basal-like), based on microarray techniques. Patients diagnosed as having breast cancer may undergo adjuvant or neoadjuvant chemotherapy, depending on the tumor size, hormone receptor, HER2/neu status, and desire for breast preservation. Patients with positive estrogen and/or progesterone receptor status benefit from treatment with selective estrogen receptor modulators such as tamoxifen or aromatase inhibitors, based on menopausal status and risk of recurrence. HER2-targeted agents such as trastuzumab and pertuzumab are used in combination with chemotherapy in patients with HER2/neu breast cancer. Triple-negative breast cancer is a unique subtype that lacks specific targets, and its treatment primarily includes chemotherapy. This article reviews the current clinical approaches to the management of patients diagnosed as having breast cancer treated with neoadjuvant and/or adjuvant chemotherapy.