An explosion of knowledge on the molecular and cellular mechanisms that mediate carcinogenesis has occurred in recent years. Although cancer has existed for over a million years in the human species, effective cures for most cancers that target molecular and cellular pathways have not been achieved. Multiple cellular targets have been examined for preventing or treating cancers including, but not limited to, transcription factors, kinase-mediated cell signaling pathways, and more recently epigenetic targeting of oncogenes and tumor suppressors, and immunomodulation such as chimeric antigen receptor-T cells. Even as the state of knowledge of cancer mechanisms increases, there is considerable room for improvement in preventing and treating cancers. Understanding how a normal cell is transformed into a cancer cell is known but there is considerable tissue and cell type specificity. This has given rise to the field of precision medicine as applied to cancer therapy. Thus, while the development of preventive and treatment regimens has increased, there are certain obstacles that need to be overcome in order to decrease cancer incidence and increase survival of cancer patients. The purpose of this review is to summarize the advances made in cancer biology and how these advances have been used to develop, and hinder, preventive, and therapeutic strategies for cancer.