Efficacy of Using Sequential Primary Circulating Prostate Cell Detection for Initial Prostate Biopsy in Men Suspected of Prostate Cancer

Background: Sequential use of circulating prostate cell (CPC) detection has been reported to potentially decrease the number of unnecessary prostate biopsies in men suspected of prostate cancer. In order to determine the real world effectiveness of the test, we present a prospective study of men referred to two hospitals from primary care physicians, one using CPC detection to determine the necessity of prostate biopsy the other not doing so. Materials and Methods: Men with a suspicion of prostate cancer because of elevated PSA >4.0ng/ml or abnormal DRE were referred to Hospitals A or B. In Hospital A all underwent 12 core TRUS biopsy, in Hospital B only men CPC (+), with mononuclear cells obtained by differential gel centrifugation identified using double immunomarking with anti-PSA and anti-P504S, were recommended to undergo TRUS biopsy. Biopsies were classifed as cancer or no-cancer. Diagnostic yields were calculated, including the number of posible biopsies that could be avoided and the number of clinically significant cancers that would be missed. Results: Totals of 649 men attended Hospital A, and 552 men attended Hospital B; there were no significant differences in age or serum PSA levels. In Hospital A, 228 (35.1%) men had prostate cancer detected, CPC detection had a sensitivity of 80.7%, a specificity of 88.6%, and a negative predictive value of 89.5%. Some 39/44 men CPC negative with a positive biopsy had low grade small volume tumors. In Hospital B, 316 (57.2%) underwent biopsy. There were no significant differences between populations in terms of CPC and biopsy results. The reduction in the number of biopsies was 40%. Conclusions: The use of sequential CPC testing in the real world gives a clear decision structure for patient management and can reduce the number of biopsies considerably.