Early identification of individuals with prostate cancer in negative biopsies

Purpose: The use of prostate specific antigen (PSA) to screen individuals for prostate cancer has changed the management of the disease, permitting early detection in men. Repeat biopsies for persistently increased PSA are not uncommon with prostate cancer never being detected in many of the men. The novel prostate cancer marker, EPCA, is expressed throughout the prostate of individuals with prostate cancer but not in those without the disease. Materials and Methods: The expression of ECPA was studied to identify those men with initially negative biopsies who were ultimately found to have prostate cancer. Negative biopsies, subsequent biopsies and prostatectomy specimens were evaluated by quantitative immunohistochemistry. Results: The EPCA staining intensity in the samples analyzed from the patient cohort with prostate carcinoma were significantly different compared to controls (p <0.001) with almost no overlap in staining results. Sensitivity of the EPCA immunohistochemistry is 84% and specificity is 85%. Conclusions: An immunohistochemical test for EPCA could serve as an adjunct to the current diagnostic approach to a patient who undergoes prostate needle biopsy, and could identify individuals with prostate cancer as much as 5 or more years earlier than the current diagnostic approach and algorithms. In addition, this test might also help limit the numbers of biopsies performed as part of subsequent routine evaluation for increased PSA.