Introduction to Predictive Biomarkers: Definitions and Characteristics

Abstract

The concept of “biomarkers” as indicators of health or disease is not new. This introductory chapter is focused on the utilization of “biomarkers” that can be detected directly in tissues from cancer patients. Within this context, biomarkers include proteins and nucleic acids and derivatives and parts thereof. The main methods of biomarker detection in cancer are reviewed, together with definitions and requirements set forth by regulatory organizations. The major challenges that this constellation of new test modalities presents to pathologists and clinicians are discussed, along with critical aspects of test cost and resultant test availability. “Precision” or “personalized medicine” appears to be an irresistible force, in turn requiring a new level of “precision pathology.” This enhanced level of assay performance may only be achieved by further refinement and development of the methods, following approaches described in this opening chapter. Already these new performance demands have radically changed the practice of pathology, particularly with reference to the diagnosis and management of malignant disease. Today we stand only at the end of the beginning of a new era of pathology practice; the ultimate end none of us as yet can foresee.