Cancer is the uncontrolled growth and spread of cells that may affect almost any tissue of the body.
Lung, prostate, breast, colorectal and stomach are the five most common cancers in the world. With more than 10 million people diagnosed with cancer and greater than 6 million cancer related deaths each year, cancer is considered the 2nd most common cause of death in industrialized countries. Tumour markers are biological substances produced by the tumour cells, generally found in very low concentrations in normal individuals, which can be measured in blood and other body fluids. Increased concentrations indicate the presence of a tumour.
An ideal tumour marker should be used for screening, diagnosis and monitoring of disease progression. However, their most important clinical application is monitoring of cancer once it has been detected and diagnosed by other methods. Appreciation of the usefulness of these markers, either individually or in parallel and recommendations of some Scientific Organizations on how they should be used has improved greatly during the past ten years. Careful interpretation of tumour marker results has led to a definite increase in their clinical significance.