Antibodies as Biomarkers in the Detection of Cancer

The early detection of cancer is vital for successful treatment as well as increasing survival rates, and the ability to come up with a reliable way to determine cancer phenotypes early could potentially save many lives. Identification of new serum antibodies as biomarkers in cancer phenotypes could prove to be an effective and precise method of detecting cancer. Tumors, specifically, tend to release into the circulatory system proteins, hormones, and other markers that can be detected in serum blood.

Despite this knowledge, there are few genomic and proteomic methods that have produced a standardized and noninvasive method of cancer screening and early detection. A vast majority of proteins released by tumor tend to be in low, if not undetectable, quantities, and have a rapid clearance rate due to the rapid metabolic rate of cancer cells.

Due to this inability to accurately quantify the secretions of cancer tumors, many scientists have turned to autoantibodies – antibodies produced by the patient’s own immune system. These antibodies have shown promise in becoming a biomarker for the detection of cancer phenotypes. Autoantibodies are produced in large quantities despite the corresponding low concentrations of antigens found among cancer cells.

New methods have emerged for the discovery of new autoantibody targets; these new methods include phage-splay libraries, recombinant cDNA expression cloning, and self-assembling protein arrays. The specificity of these targets have proved to be an issue in these novel methods because scientists must avoid targets identified by antibodies present in patients that do not have cancer or have benign tumors. These methods are being refined to improve their sensitivity and specificity.

Exploring alternative, novel biomarkers for diagnostic potential is a rapidly growing field, and one that Emory researchers have not shied away from. Emory University has pioneered several biomarker assays to predict cancer phenotypes. Many of these cancers are known to be more chemotherapy-resistant than others, and this resistance is attributable to the expression of certain genes in cancer cells. Emory University researchers identified the expression of certain genes in small cell lung cancer. By assaying the expression of these genes in tumors, cancers can be identified quickly and more targeted, individualized therapies can be developed.

Emory researchers have identified RNA biomarkers to detect prostate cancers that could not only screen, but accurately predict recurrence of certain prostate cancers reliably. Researchers have also identified DNA biomarkers in the form of cell-free DNA to accurately identify and diagnose renal cell carcinomas.

Although Emory has not yet delved into the biomarker potential of antibodies, researchers have identified antibodies in the treatment of certain cancers, such as myelomas (Elotuzumab) and mesotheliomas (Durvalumab). At the forefront of biomedical research and discovery, it will not be long before Emory further explores the multipurpose of antibodies in the rapidly growing field of oncology.

Johannes W. Pedersen, Hans H. Wandall; Autoantibodies as Biomarkers in Cancer, Laboratory Medicine, Volume 42, Issue 10, 1 October 2011, Pages 623–628,