The value of percentage free prostate specific antigen (PSA) in the detection of prostate cancer among patients with intermediate levels of total PSA (4.0–10.0 ng/mL) in Nigeria
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Date
2012
Authors
Ezenwa, E.V.
Tijani, K.H.
Jeje, E.A.
Soriyan, O.O.
Ogunjimi, M.A.
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Objectives: To assess the value of percentage free prostate-specific antigen (%fPSA) in the detection of prostate cancer among Nigerian men with an intermediate total PSA level (4–10 ng/mL), and to show if the optimum threshold for biopsy is different from Caucasian values when the widely used (six-core, digitally directed) prostate biopsy protocol in Nigerians is applied.
Patients and methods: The study included 105 patients aged >50 years, with a palpably benign prostate gland and intermediate levels of total PSA (4–10 ng/mL). These patients had a free PSA assay and a transrectal digitally directed six-core biopsy of the prostate. The %fPSA was calculated and the optimum threshold value for detecting prostate cancer was determined.
Results: The mean (SD) age of the patients was 64.4 (6.6) years and their mean (SD) total PSA level was 6.6 (1.7) ng/mL. Of these men 14 (13.3%) had cancer of the prostatedetected by the prostate biopsy. The %fPSA level related directly to
sensitivity values but inversely to the specificity and the positive predictive values.
The best threshold of %fPSA for detecting cancer in these men was <40%, with
a sensitivity of 100%, specificity of 93.4% and a positive predictive value of 70%
(P<0.05).
Conclusions: In evaluating Nigerian patients with a palpably benign prostate
gland and within the intermediate total PSA range, when digitally directed biopsy
protocol is adopted, a %fPSA threshold of <40% will detect significant percentage
of those with prostate cancer, with a minimal number of unnecessary biopsies. This
value differs from that reported in western studies in which transrectal ultrasonography-
directed biopsy was used
Description
Staff publications
Keywords
prostate cancer , Prostate specific antigen , Free PSA , Nigerian men , Research Subject Categories::MEDICINE::Surgery
Citation
Ezenwa EV, Tijani KH, Jeje EA, Soriyan OO, Ogunjimi MA. The value of percentage free prostate specific antigen (PSA) in the detection of prostate cancer among patients with intermediate levels of total PSA (4.0–10.0 ng/mL) in Nigeria. Arab Journal of Urology 2012;10:394–401