Use of tumour markers in cancer diagnosis and treatment.

This paper examines the laboratory identification of tumour markers--substances present in the blood and urine that are released by tumour cells or by the patient in response to a tumour. A general consideration of what constitutes a useful tumour marker is followed by a description of some specific tumour markers currently used in clinical practice. Reference is made to the potential impact of recent cancer research on initiatives for early cancer detection by testing blood.