Cancer Stem Cell Biomarkers

The National Cancer Institute (NCI) definition of a biomarker is, ‘A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. A biomarker may be used to see how well the body responds to a treatment for a disease or condition. Also called molecular marker and signature molecule.’ An enormous number of papers describe biomarkers in medicine in general, and in cancer in particular. It is, however, not always easy to use existing markers in clinical practice, because of their specificity and sensitivity. In this chapter, we critically discuss recent discoveries in cancer stem cells and biomarkers, suggesting possible uses for clinical applications.