Cancer Biomarker Antigens 

Cancer biomarkers are substances that can be found in the body when cancer is present. 

They are usually found in the blood or urine. They can be products of cancer cells or of the body in response to cancer. Most tumor markers are proteins. Tumor markers are playing an increasingly important role in cancer detection and management. These laboratory-based tests are potentially useful in screening for early malignancy, aiding cancer diagnosis, determining prognosis, surveillance following curative surgery for cancer, up front predicting drug response or resistance, and monitoring therapy 

in advanced disease. In asymptomatic subjects, tumor markers are potentially used in screening for early malignancy. In symptomatic patients, markers may help in the differential diagnosis of benign and malignant disease. Following diagnosis and surgical removal of a malignancy, markers may be used for assessing prognosis, postoperative surveillance, therapy prediction and monitoring response to systemic therapy. Irrespective of its application, an ideal tumor marker should exhibit the following characteristics:

•  Possess a high positive and negative predictive value;

•  Have an inexpensive, simple, standardized and automated assay with clearly defined reference limits;

•  Be acceptable to subjects undergoing the test;

•  Have its clinical value validated in a large prospective trial.