Optimal predictors of prostate cancer on repeat prostate biopsy: A prospective study of 1,051 men

Purpose: We compare the ability of total prostate specific antigen (PSA), percent free PSA, PSA density and transition zone PSA density to predict the outcome of repeat prostatic biopsy in men with serum total PSA 4 to 10 ng./ml. who were diagnosed with benign prostatic hyperplasia after initial biopsy. Materials and Methods: In this prospective study 1,051 men with total PSA 4 to 10 ng./ml. underwent transrectal ultrasound guided sextant biopsy with 2 additional transition zone biopsies. In 254 subjects biopsy specimens were also obtained from suspicious areas identified during transrectal ultrasound and digital rectal examination. All subjects with biopsy specimens negative for prostate cancer underwent repeat biopsy 6 weeks after initial biopsy. The ability of total PSA, percent free PSA, PSA density and transition zone PSA density to improve the diagnostic power of PSA testing was assessed with univariate and multivariate analyses as well as receiver operating characteristics (ROC) curves. Results: Initial biopsy was positive (prostate cancer) in 231 and negative (benign prostatic hyperplasia) in 820 of the 1,051 subjects. Prostate cancer was detected on repeat biopsy in 10% of subjects (83 of 820) with negative initial biopsy. Percent free PSA and transition zone PSA density were the most accurate predictors of prostate cancer in these subjects. At a cutoff of 30% percent free PSA would have detected 90% of cancers (sensitivity) and eliminated 50% of unnecessary repeat biopsies (specificity). Sensitivity and specificity of transition zone PSA density at a cutoff of 0.26 ng./ml./cc was 78% and 52%, respectively. ROC curve analysis also showed that percent free PSA was a significantly better predictor of repeat biopsy results than total PSA, PSA density and transition zone PSA density. The area under the ROC curve was 74.5% for percent free PSA, 69.1% for transition zone PSA density, 61.8% for PSA density and 60.3% for total PSA. Conclusions: At least 10% of patients with negative initial prostatic biopsy results will be diagnosed with prostate cancer on repeat biopsy. Percent free PSA and transition zone PSA density enhance the specificity of PSA testing compared to total PSA or PSA density when determining which patients should undergo repeat biopsy. Repeat biopsy should be performed in patients with percent free PSA less than 30% or transition zone PSA density 0.26 ng./ml./cc or greater. In our study percent free PSA was the most accurate predictor of prostate cancer in repeat biopsy specimens.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Total and transition zone prostate volume and age: How do they affect the utility of PSA-based diagnostic parameters for early prostate cancer detection?

Objectives. To define the role of total prostate (TP) volume, transition zone (TZ) volume, and age as determinants of the utility of prostate-specific antigen (PSA)-based diagnostic parameters for early detection of prostate cancer (PCa) in a prospective multicenter study. Methods. The study participants were 974 consecutive men with serum total PSA (tPSA) levels of 4 to 10 ng/mL who were referred for early PCa detection or lower urinary tract symptoms. All patients underwent prostate ultrasound examination and sextant biopsy with two additional TZ biopsies. In patients with negative initial biopsies, repeated biopsies were performed at 6 weeks. tPSA, the free/total PSA ratio (f/t PSA), PSA density of the TZ (PSA-TZ), PSA density (PSAD), and PSA velocity (PSAV) were determined and compared across TP volume strata of 30 cm3 or less and greater than 30 cm3, TZ volume strata of 20 cm3 or less and greater than 20 cm3, and various age groups to evaluate the need for volume and/or age-specific reference ranges. Results. PCa was found in 345 (35.4%) of 974 patients and benign prostatic tissue was found in 629 (64.6%) of 947 patients. Across TP volume strata, significantly higher values of tPSA (P <0.01), PSA-TZ, PSAD (P <0.001), and PSAV (P <0.05) and lower values of f/t PSA (P <0.001) were observed in patients with PCa than in those without PCa. Similar results were obtained with respect to TZ volume strata, except in the case of PSAV (P <0.05). tPSA, PSA-TZ, and PSAD were significantly higher (P <0.05) in patients with PCa than in those without PCa for all corresponding age ranges. In patients with PCa, f/t PSA was significantly lower (P <0.001) within the same age ranges. Within each group (PCa or benign), f/t PSA, PSAD, PSA-TZ, and PSAV values were unaffected by age strata. However, PSA parameters dependent on prostate volume (PSAD, PSA-TZ) were statistically lower (P <0.001) in prostates with a higher TP volume (greater than 30 cm3) and TZ volume (greater than 20 cm3); f/t PSA values were unaffected by TP and TZ volumes. Conclusions. f/t PSA and PSA-TZ were the most powerful parameters to differentiate between benign prostatic tissue and PCa. f/t PSA was the sole parameter unaffected by age and prostate volume. We believe new volume-specific cutpoints, as presented in the current study, should be employed when using PSAD and PSA-TZ for the early detection of PCa.SCOPUS: ar.jinfo:eu-repo/semantics/publishe