Tumor markers

Tumor markers are substances produced by a tumor or by the host in response to a cancer cell. They can be found in cells, tissues, or body fluids and measured qualitatively or quantitatively by methods including chemical, immunological, molecular, and mass spectrometry to identify the presence of cancer. This chapter describes the ideal characteristics, classes, and potential applications of tumor markers as well as analytical and clinical considerations. The most commonly used tumor markers in clinical practice for breast, gastrointestinal, genitourinary, hepatocellular, lung, ovarian, and thyroid cancers are described.