Cancer accounts for approximately 13 % of all deaths worldwide. Development of stratification biomarkers, for cancer screening, diagnosis, monitoring, and treatment optimization, is a vital concept to facilitate disease prevention and drug development. The advent of stratified medicine should result in the safer, more effective use of therapeutic drugs to treat cancer, and in reducing the cost associated with inappropriate therapeutic regimens; however, many barriers delay the use of biomarkers in drug development and clinical practice. Since the incorporation of biomarkers in clinical practice might have additional initial costs, the question arises regarding whether the improvement in outcomes is reached at a realistic additional cost. This review presents an overview of economic issues surrounding biomarkers in cancer treatment optimization.