In the emerging era of personalized medicine, biomarkers may demonstrate viable pathways in the understanding of an individual's response to a particular treatment plan. Biomarkers are biological molecules found in blood, other body fluids or tissues. Biomarkers can be a sign of a normal/abnormal process, or of a condition or disease.

Biomarkers can be further divided into the categories of predictive or prognostic. Prognostic biomarkers provide information about the natural history of a disease and can help determine probable clinical outcomes. Predictive biomarkers provide information about the likelihood of response or lack of response to a given treatment plan. A predictive biomarker is a biomarker that is present prior to an event occurring and which may predict that outcome.

Integrating biomarkers into routine clinical practice may help oncologists select an appropriate treatment plan for the right patient. The advances in diagnostic tools used to measure or evaluate an indicator of a normal biological process, pathogenic process, or response to a therapeutic intervention may also permit clinicians to individualize or personalize treatment for patients by identifying those who may or may not benefit from a particular treatment plan.