Received on May 27, 2008
Accepted on September 19, 2008

Reviews

Emerging Biomarkers for the Diagnosis and Prognosis of Prostate Cancer

¹ Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada, and Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
² Abbott Laboratories, Abbott Park, IL
³ Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada, and Department of Clinical Biochemistry, University Health Network and Toronto Medical Laboratories, Toronto, Ontario, Canada

^* To whom correspondence should be addressed. E-mail: ediamandis{at}mtsinai.on.ca.

BACKGROUND: Early detection of prostate cancer (CaP), the most prevalent cancer and the second-leading cause of death in men, has proved difficult, and current detection methods are inadequate. Prostate-specific antigen (PSA) testing is a significant advance for early diagnosis of patients with CaP.

CONTENT: PSA is produced almost exclusively in the prostate, and abnormalities of this organ are frequently associated with increased serum concentrations. Because of PSA's lack of specificity for CaP, however, many patients undergo unnecessary biopsies or treatments for benign or latent tumors, respectively. Thus, a more specific method of CaP detection is required to augment or replace screening with PSA. The focus recently has been on creating cost-effective assays for circulating protein biomarkers in the blood, but because of the heterogeneity of CaP, it has become clear that this effort will be a formidable challenge. Each marker will require proper validation to ensure clinical utility. Although much work has been done on variations of the PSA test (i.e., velocity, density, free vs bound, proisoforms) with limited usefulness, there are many emerging markers at various stages of development that show some promise for CaP diagnosis. These markers include kallikrein-related peptidase 2 (KLK2), early prostate cancer antigen (EPCA), PCA3, hepsin, prostate stem cell antigen, and -methylacyl-CoA racemase (AMACR). We review biomarkers under investigation for the early diagnosis and management of prostate cancer.

SUMMARY: It is hoped that the use of panels of markers can improve CaP diagnosis and prognosis and help predict the therapeutic response in CaP patients.