This work covers the pathophysiology of cancer, exploring the difficulty of optimal treatment due to the complexity and diversity of cancer types. The search for distinctive molecular biology characteristics of tumor cells is especially relevant in the identification of overexpressed receptors and proteins that can be used as a target for cancer treatment. We highlight the main therapeutic modalities, particularly conventional systemic chemotherapy, addressing its mechanisms of action, therapeutic classes and even the toxic effects. We also describe the main tumor markers, their importance in the diagnosis and treatment of cancer, and the specificity of tumor cells. The first chapters serve as an introduction to the central topic of this book, targeted therapy. Key aspects of target therapy, such as classes of drugs, immunotherapy, monoclonal antibodies, checkpoint inhibitors, cancer vaccines and tyrosine kinase inhibitors are presented, and, for each one, the benefits, as well as the adverse effects are reported. Chapter 6 compares conventional systemic chemotherapy and targeted therapy, identifies the risks and benefits and also the eligibility criteria for patient care. The possibility of targeted therapy replacing conventional chemotherapy is discussed while reviewing studies that demonstrate the benefits of combining both types of treatment. Finally, the introduction of pharmaceutical nanotechnology to improve antineoplastic agents is addressed in the last chapter and sets the direction for future research in cancer treatment. This is a valuable resource for many health professionals including physicians, pharmacists, nurses, researchers and students interested in the field of oncology.