Change of subtype in patients with advanced breast cancer after neoadjuvant chemotherapy

Heterogeneity of breast cancer has been a challenge for treatment. Many studies have been conducted to improve the treatment outcome through identification of this heterogeneity. Among identified biologic makers, estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2 have been used importantly as not only treatment target but also predicting prognosis. Nowadays, neoadjuvant chemotherapy is commonly used in patients with advanced breast cancer at diagnosis. Herein, we report the case in the which breast cancer subtype was changed after neoadjuvant chemotherapy.