Cancer biomarkers can be derived from tumor cells or neighboring cells within the tumor microenvironment. Over the past few decades, various molecular markers, including DNA (mutations, copy number variations), RNA (mRNA, microRNA, circular RNA), proteins, and metabolites, have been identified with the aid of rapidly evolving technologies. Some of these markers have demonstrated potential clinical utility, while others have provided new insights into the deregulation of normal molecular and cellular processes that lead to tumorigenesis. Publications in this special issue of the Biomedical Journal introduce contemporary approaches aimed at enhancing cancer diagnosis, and monitoring of cancer and treatment options, with the ultimate goal of reducing mortality. These studies highlight the importance of integrating advanced technologies with clinical strategies for treatment of cancer.