PTU - Polskie Towarzystwo Urologiczne
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Prostate biopsy performed due to elevated prostate specific antigen (PSA) level – assessment of the prostate cancer detectability
Article published in Urologia Polska 2008/61/Supl. 1.

authors

Michał Malkowski, Wojciech Cieślikowski Jr, Leszek Michalak, Łukasz Wojnar, Witold Malendowicz, Ryszard Prędki, Zbigniew Kwias
Klinika Urologii i Onkologii Urologicznej UM w Poznaniu

summary

Introduction.

Prostate Cancer (PC) is the third most frequently diagnosed cancer in males in Poland. Aggressive diagnostic procedures play the key role in treatment effectiveness and mortality reduction. Wider indications for prostate biopsy increase the number of procedures, sometimes unnecessarily performed.

Objectives.

The aim of the study was to assess the detectability of PC in patients referred to the prostate biopsy only by increased PSA. Factors increasing the risk of diagnosis of PC and unnecessary biopsies were evaluated.

Materials and methods.

Out of 628 transrectal ultrasonography (TRUS)-controlled prostate biopsies carried out in 2005, 458 not previously diagnosed patients (with full clinical data) were evaluated. Indications for biopsy: PSA level above age ranges, suspicion in the free-to-total PSA relation, positive digital rectal examination (DRE) and/ or abnormal TRUS. 6 to 12 specimens were obtained from both lobes depending on prostate volume, abnormal TRUS imaging or structures with abundant vasculature in power Doppler examination. The age of the studied population was 40-92 years (mean 66.4 +/- 8.62), PSA level 0.71 to 488.6 ng/ml. Data were evaluated in three ranges of PSA: 4.0-10.0; 10.0-20.0; >20 ng/ml. The analysis of the PSA density (PSAD) was performed within ranges.

Results.

PC was diagnosed in 34.94 % (160/458) of patients. The positive predictive value for PSA assessed in ranges (4–10 ng/ml, 10-20 ng/ml, >20 ng/ml) was 21.83% (50/229), 37.5% (48/128) and 72.94 % (62/85), respectively. Mean age in groups with positive and negative prostate biopsy was 67.5 and 65.8. Mean prostate volume was 45.36 cm3 and 57.89 cm3, respectively. Mean PSAD level for positive and negative biopsy in range 4–10 ng/ml was 0.21 ng/g and 0.15 ng/g, in range 10-20 ng/ml-0.40 ng/g and 0.28 ng/g, and above 20 ng/ml-3.59 and 0.78.

Conclusions.

1. PC detection in pathologic assessment increases with an increased PSA level. 2. The frequency of carcinoma detection is the lowest in the population of men with the lowest PSA levels. 3. The probability of unnecessary biopsies is higher in patients with low PSA levels.