This is a single arm, multicenter, and retrospective study. About 200 breast cancer patients' data from medical records are expected to collect and analyze in this retrospective study. The data collection from medical records of breast cancer patients who approved to use NHI to pay for CRF treatment drug will include the demographic information, disease characteristics and cancer treatment information, fatigue score by visual analog fatigue scale, fatigue clinical global impression, CRF pharmacological treatment record, hematological lab data, ECOG, cancer drug compliance record, overall clinical evaluation after CRF treatment by physicians and patient's expectation to continue CRF treatment etc. Data of three return visits (i.e. at the time of before CRF treatment, after 4 times of CRF treatment and CRF treatment completed) per patient will be collected from medical records to analysis within the period that patient is receiving NHI-covered CRF treatment.
