ABSTRACT
Breast cancer， as a kind of malignant tumor with high incidence rate in female population， poses a great threat to people's health. At present， chemotherapy is the main treatment for breast cancer besides surgery and radiotherapy. However， chemotherapy is often accompanied by multidrug resistance （MDR）， which results in a series of severe consequences such as low efficacy， relapse of cancer after drug withdrawal， increased consumption of medical resources， and increased burden of medical system. Previous studies showed that the mechanism of MDR in breast cancer was quite complex， involving drug efflux， deoxyribonucleic acid （DNA） damage repair， tumor microenvironment， autophagy， epigenetic regulation， tumor stem cells， lipid metabolism， and so on. In addition， there were extensive connections among the mechanisms of MDR. Therefore， it is necessary to reveal the mechanism of MDR and develop corresponding drugs to reverse MDR， thus improving the effect of chemotherapy on treating breast cancer. Chinese medicine has the advantages of high efficiency， low toxicity， multi targets， and overall regulation. Various studies found that Chinese medicine monomer， single drug， and compound were able to reverse MDR in breast cancer by regulating the expression of drug efflux protein， promoting apoptosis， and regulating autophagy， showing the potential of anti-MDR in breast cancer. This paper summarized the research progress of the mechanism of MDR in breast cancer and the strategies of Chinese medicine in coping with MDR in breas cancer in recent years， and provided references for further research.