Fundamental Considerations of Targeted Drug Therapies for Breast Cancer

Breast cancer is a complex disease for which pharmacological treatment does not guarantee success or cure. In addition, current pharmacological therapies induce unwanted side effects due to their lack of specificity or selectivity. Therefore, it is necessary to develop new therapeutic options to improve these aspects. Currently, phytochemicals with antineoplastic properties have been identified from a wide variety of plant sources, and new therapeutic options have been developed based on the conjugation of drugs with polymeric matrices, resulting in nanoparticles or hydrogels with improved properties. Some antineoplastic drugs have been conjugated with antibodies to improve their selectivity and specificity. One of the most important advances in the treatment of breast cancer has been the development of cyclin inhibitors and gene therapy. This review provides an overview of drugs derived from medicinal plants and polymeric matrices with high potential for use in the treatment of breast cancer. We also highlight the clinical evidence for the use of anti-HER2 monoclonal antibodies and cyclin inhibitors in breast cancer, as well as the advantages of using conjugated antibodies. Finally, we mention some considerations that should be taken into account in the search for new therapeutic agents from phytochemicals, polymers, antibodies, cyclin inhibitors, and gene therapy focused on the treatment of breast cancer.