Early change of tumor size measured on magnetic resonance imaging (MRI) is a good predictor of final response after neoadjuvant chemotherapy. However, even if the cells respond to treatment, it takes some time for the tumor to shrink. Substantial research effort has been spent on investigating whether other information provided by MRI may serve as earlier response indicators than size change. In vivo proton MR spectroscopy (1H-MRS) has been proven helpful for the detection and therapy response monitoring of breast cancer based on choline-containing compounds (tCho) .However, the usefulness of 1H-MRS lipid signal for therapy response prediction is less established. The purpose of our study was to compare changes in 1H-MRS lipids and in tumor size at early times after neoadjuvant chemotherapy between who achieved pathological complete response (pCR) and those who did not.