Breast cancer is the most common type of malignancy in women worldwide. There are several factors associated with breast cancer for manifesting a heterogeneous disease in nature. Chemotherapeutic drugs significantly reduce the mortality rate of breast cancer. The recent development of chemotherapeutic drugs is targeting heterogeneity by including hormone receptors, expression of genes, epidermal growth factors, etc. The therapeutic response is dependent on a variety of factors, including stages, subtypes, metastasis, etc. For example,- endocrine therapy is preferred for positive hormone response in luminal breast cancer. In the recent therapeutic regimens, CDK4/6 quenchers are emerged, which regulate cell cycle by interacting with cyclin D1. It is also because, in the case of resistant hormonal therapy, tumors still showed its dependency on CDK4/6- cyclin D1 for proliferation. Apart from chemotherapy, immunotherapy is one of the emerging therapeutical regimens for breast cancer. There are also a number of vaccination approaches against breast cancer, including Nelipepimut–S, derived from the extracellular domain of the human epidermal factor receptor, which is used as a vaccine to prevent the reoccurrence of refractory breast cancer. Epithelial-to-mesenchymal transition (EMT) is a crucial mechanism for breast cancer progression. Currently, EMT inhibitor is used for preclinical testing to further used as a drug molecule to treat breast cancer. Thus, the advancement of chemo- or immunotherapy can substitute over invasive treatment strategies such as the surgical method for the treatment of breast cancer.
Keywords: Breast cancer, Cyclin-dependent kinases 4 and 6 inhibitors, Chemotherapy, Human epidermal growth factor receptor, Immunotherapy.