The Patient Equation

2Inside the Equations

To think effectively about these new types of data and the value they can add to our disease models, we need to start by talking about “biomarkers” and “biospecimens.” As with so many things in science and medicine, they're just fancy words for relatively simple things. We usually think about biomarkers and biospecimens in the context of traditional medical measurements, our genes, and physical tissue samples.

A biomarker, according to the International Programme on Chemical Safety, led by the World Health Organization, is “any substance, structure, or process that can be measured in the body or its products and influence or predict the incidence of outcome or disease.”¹ In slightly simpler terms, it's something we can measure that tells us something about a person's disease. If someone has cancer, for example, we can go in and take a sample of their tumor—a biopsy. The tissue sample from that biopsy—a biospecimen—will be used by pathologists and evaluated in laboratories. Microscopes and assays are used to examine the physical and biochemical properties of that tumor, looking for useful biomarkers. We can search for specific sequences of DNA, such as a particular mutation that allows us to predict how aggressive the cancer might be. Or we can examine the shape of the cells or the presence of estrogen or progesterone receptors. All of this measuring and evaluating is typically done in real time, in the best cases helping to decide on the right course of ...