e-ISSN 2329-0072




Isoforms of PSA (prostate-specific antigen) in the diagnosis of prostate cancer

Christos Pelekanos, Jörg Beardi, Dietger Jonas, Gerhard M Oremek

Med Sci Tech 2008; 49(1): RA23-25

ID: 881588

Available online:

Published: 2008-03-21

Introduction: Prostatic tumor tissue produce more complex form of PSA (cPSA) than free PSA (fPSA). Investigating possibilities for early detection of prostate cancer cPSA is supposed to be more sensitive than the ratio of fPSA and tPSA. The aim of the study was to evaluate the diagnostic value of cPSA in early detection of malignant prostatic tumor. Material and methods: We evaluated the new cPSA test comparing it with the already routinely used fPSA and tPSA test. The study comprised a total of 500 patients with different urological affections attending the Division of Urology, University of Frankfurt, Germany. Biopsy and histologic examination were done in all cases. The histologic report was compared with the laboratory results done by imunologic and electrochemiluminescence methods.Results: 200 apparently healthy donors served as a control group. 141 had a benign tumor of the prostatic gland and 159 had a malignant process diagnosed by histological examination. The cut-off level for cPSA was at 2,3 ng/ml. Within a range of 2,0-4,0 ng/ml tPSA and a cut off 2,3 ng/ml for cPSA we found a tumor sensitivity of the test in 92%, proved by the histologic report. cPSA allows us a detection of malignant process at an earlier stage than tPSA and even within a „normal range“ of tPSA beween 2,0-4,0 ng/ml. At a concentration of tPSA beween 4,1 and 10 ng/ml we talk about a grey zone. With measurement of cPSA we achieved in 71% of our cases a more specific result than in obtaining the PSA ratio. We didn`t observe any adverse result in the concentration of cPSA concerning manipulation of the prostatic gland as seen before in the measurement of fPSA. cPSA is much more stable regarding to transportation and storage. There is no loss of concentration level observed up to –20°C, whereas fPSA shows a loss of 10%. Conclusions: We conclude that the new tumor marker cPSA has a higher value for specivity in the concentration range of tPSA from 2,0-4,0 ng/ml and as well in the grey zone beween 4,0-10 ng/ml. (Clin Exp Med Lett
2008; 49(1): 23-25)

Keywords: prostate cancer