Intermediate versus low or high prostate-specific antigen density level: Comparison of cancer detection rate between 12- and 18-core prostate biopsy

Abstract

To compare the diagnostic values of 12- and 18-core biopsies with respect to prostate-specific antigen (PSA) levels, prostate volumes (PV) and prostate-specific antigen density (PSAD). Transrectal ultrasound-guided prostate biopsies were performed on 233 patients at a single tertiary academic center. Patients were prospectively randomized to the two protocols (12 or 18 core). The cancer detection rates achieved using these two methods were analyzed at different PSA levels, PVs and PSADs. Considering PSA level and PV simultaneously, patients were stratified into four groups (group A: PSA < 7 ng/ml and PV ≥ 45 cm(3); group B: PSA < 7 ng/ml and PV < 45 cm(3); group C: PSA ≥ 7 ng/ml and PV ≥ 45 cm(3); group D: PSA ≥ 7 ng/ml and PV < 45 cm(3)). 18-core biopsy had a higher cancer detection rate than 12-core biopsy only in group C (55.2% vs 24.1%, p = 0.015). The 233 patients were also stratified into three groups according to PSAD level: the low PSAD group (PSAD < 0.15 ng/ml/cm(3)), the intermediate PSAD group (0.15 ng/ml/cm(3) ≤ PSAD < 0.25 ng/ml/cm(3)) and the high PSAD group (PSAD ≥ 0.25 ng/ml/cm(3)). In the intermediate PSAD group, 18-core biopsy had a higher cancer detection rate than 12-core biopsy (54.2% vs 28.9%, p = 0.048). An 18-core biopsy is more useful than a 12-core biopsy for detecting prostate cancer in patients with high PSA and large PV, that is, with intermediate PSAD level.