Negative predictive value of systematic ultrasound-guided prostate biopsy: which tumours do we miss?

BACKGROUND: The aim of the study was the determination of the negative predictive value of sextant core prostate biopsy. PATIENTS AND METHODS: Prostate cancer was diagnosed in 126 patients by systematic ultrasound-guided sextant biopsy and was subsequently treated with radical prostatectomy. The prostatectomy specimens were examined histopathologically using the whole-mount section technique. RESULTS: 81 patients were diagnosed with unilateral and 45 with bilateral prostate cancer after biopsy. In 15/81 patients, the diagnosis of unilateral disease was confirmed by the whole-mount sections; 66 patients turned out to have bilateral disease. In 14/66 cases, the missed tumour foci were diminutive. In the remaining 52 patients, an erroneous diagnosis of unilateral prostate cancer had been made after biopsy, although the missed tumour foci were not diminutive. The negative predictive value of sextant core biopsy with respect to unilateral disease was 36%. CONCLUSION: An unexpectedly high number of tumour foci are missed by systematic ultrasound-guided sextant prostate biopsy.

Rectum dose reduction and individual treatment plan optimization for high-dose-rate prostate brachytherapy.

PURPOSE: Different doses and techniques used in high-dose-rate (HDR) prostate brachytherapy make it difficult to define universal quality parameters. The aim of this study was to develop individual, objective parameters for the evaluation of an HDR brachytherapy plan for prostate radiation. METHODS: Fifty-three patients who received an HDR brachytherapy boost after external radiation were analyzed in this study. Brachytherapy was performed with a (192)Ir source after ultrasound-guided, transperineal metal needle application followed by removal of the ultrasound probe to reduce organ dose levels at the anterior rectum wall. The rectum and prostate locations as well as the dose at the anterior rectum wall were estimated under the anatomical conditions of HDR prostate brachytherapy. The doses at the organs at risk (rectum and urethra) were analyzed for several parameters, which were compared to values of former patients before the start of treatment. In cases of major deviations, modifications of the treatment plan were performed before starting the treatment. RESULTS: Deflating of the water balloon led to an increase of the space between the anterior rectal wall and the dorsal margin of the prostate (mean, 6mm; 1-10mm). The dose of the introduced "virtual rectum," represented by the ventral surface of the ultrasound probe, in the treatment plan correlated to dose measurements in the rectum. Pretreatment evaluation and comparison of the established individual quality parameters led in two cases to a treatment plan modification. CONCLUSIONS: This method allows a fast and objective individual brachytherapy treatment plan evaluation and improvement.

Adjuvant cisplatin plus methotrexate versus methotrexate, vinblastine, epirubicin, and cisplatin in locally advanced bladder cancer: results of a randomized, multicenter, phase III trial (AUO-AB 05/95).

PURPOSE: Radical cystectomy as standard treatment of muscle-invasive urothelial carcinoma of the urinary bladder cures less than 50% of patients with locally advanced bladder cancer. We compared two adjuvant combination chemotherapies in patients with stage pT3a-4a and/or pathologic node-positive transitional-cell carcinoma of the bladder after radical cystectomy. PATIENTS AND METHODS: A total of 327 patients were randomly assigned to either adjuvant systemic chemotherapy with three cycles of cisplatin 70 mg/qm(2) on day 1 and methotrexate 40 mg/qm(2) on days 8 and 15 of a 21-day cycle (CM) or three cycles of methotrexate 30 mg/qm(2) on days 1, 15, and 22, vinblastine 3 mg/qm(2) on days 2, 15, and 22, epirubicin 45 mg/qm(2) on day 2, and cisplatin 70 mg/qm(2) on day 2 of a 28-day cycle (M-VEC). RESULTS: The hazard ratio for progression-free survival as the primary end point was 1.13 (90% CI, 0.86 to 1.48) for 163 CM patients compared with 164 M-VEC patients whose right-hand limit remained below the upper bound compatible with the noninferiority hypothesis (alpha = .0403). The 5-year progression-free, tumor-specific, and overall survival rates (point estimates +/- SE) for CM versus M-VEC were 46.3% +/- 4.6% v 48.8% +/- 4.5%, 52.0% +/- 4.6% v 52.3% +/- 4.8%, and 46.1% +/- 4.3% v 45.1% +/- 4.6%, respectively. WHO grade 3 and 4 leukopenia occurred in 7.0% of patients treated with CM and 22.2% of patients treated with M-VEC (P < .0001). CONCLUSION: CM cannot be considered inferior to M-VEC with regard to progression-free survival of patients with locally advanced bladder cancer after radical cystectomy. Moreover, patients receiving adjuvant CM combination therapy experienced significantly less grade 3 and 4 leukopenia than patients treated with M-VEC.

Semi-quantitative immunochromatographic test for prostate specific antigen in whole blood: tossing the coin to predict prostate cancer?

OBJECTIVES: A strip test for the semi-quantitative determination of prostate specific antigen (PSA) based on whole blood was evaluated by the Working Group on Laboratory Diagnostics of the German Urological Association. METHODS: In 301 men (156 volunteers and 145 referred patients, mean ages 57 years and 64 years) handling and capability of the strip test to predict PSA serum concentrations (Access Hybritech, Beckman Coulter, Inc., Fullerton, CA, USA) relative to a cutoff of 4 micro g/l were investigated. For patients, the strip test was performed by investigators, volunteers accomplished it according to leaflet instructions. Each test result was interpreted by both, the patient/volunteer and an investigator. RESULTS: 24% of the volunteers required assistance with test performance. The overall agreement between Access PSA (range 0.1-29.7) and strip test was 76% (read by participants) and 79% (read by investigators). Within the PSA ranges 0.1-3, 3.1-5 and 5.1-10, participants yielded agreement rates of 89%, 40% and 56%, respectively. Studying the 2.1-10 PSA range most relevant for prostate cancer screening, agreement rate (53%), sensitivity (50%) and specificity (67%) were barely superior to random chance. Volunteers alone (PSA range 0.1-11.3 micro g/l) yielded a specificity of 92%, however, all PSA values above the cutoff (n=8) went unrecognized and all positive strip tests (n=12) were incorrect (sensitivity 0%, positive predictive value 0%). CONCLUSIONS: Test handling and interpretation was difficult. The rate of false strip test results is disappointing even for PSA ranges remote from the cutoff. In its present form the strip test fails to meet the clinical requirements and its launch to the market was therefore discontinued.

A new modification of the Chiron ACS assay for total prostate-specific antigen achieves equimolar response characteristics and improves the detection of prostate cancer.

Nonequimolar-response assays for prostate-specific antigen (PSA) are criticized for overestimating total PSA in some men without prostate cancer (PCA), and underestimating total PSA in some men with PCA. We recently studied three nonequimolar-response PSA assays that had undergone modifications. While two of the studied assays achieved equimolar-response characteristics with improved areas under receiver operating characteristic (ROC) curves (AUC), the modification of the Chiron ACS PSA assay (ACS PSA2, Chiron) failed to achieve this. Recently, the ACS assay underwent another modification (ACS PSA, Bayer), which we investigated. Sera from 305 men (155 without and 150 with PCA, PSA > or = 2 and < or = 30 microg/l, Tandem-E) were measured using both modifications of the ACS assay and equimolar-response reference methods (Tandem-R free and Tandem-E, Hybritech). Molar response relative to the reference method and clinical performance (comparison of AUCs) between the previous and new ACS assay modifications were studied. The new modification of the ACS assay (ACS PSA, Bayer) achieved equimolar-response characteristics but reported lower values (average 10%) than the Tandem-E assay. Compared to the previous modification (ACS PSA2, Chiron), a 3% improvement in AUC (p = 0.01) was found. Using results of the redesigned equimolar-response assay (ACS PSA, Bayer), we calculated that 6 of 155 men without PCA in this sample set could be spared unnecessary biopsy compared with the previous nonequimolar-response assay (ACS PSA2, Chiron) without missing additional PCA (90% sensitivity). These data provide additional evidence for clinical advantages of equimolar-response over nonequimolar-response PSA assay formats.

Combining free and total prostate specific antigen assays from different manufacturers: the pitfalls.

OBJECTIVES: We investigated the impact of interchanging free prostate specific antigen (f-PSA) concentrations from 10 different assays over a reference total PSA (t-PSA) on predicting prostate histology with free-to-total PSA ratios (f/t-PSA). METHODS: Archival sera from 80 t-PSA- and age-matched pairs of histologically confirmed prostate cancer (PCA) and benign prostatic hyperplasia (BPH) patients with t-PSA levels between 2 and 25 microg/l were investigated. Serum aliquots were analyzed for t- and f-PSA using a reference method (Access, Beckmann-Coulter Hybritech) and 10 commercially available f-PSA assays. Passing Bablok and linear regression were performed to investigate the interassay agreement between f-PSA assays. To compare diagnostic performance, ROC curves for PCA detection were calculated for the 10 f/t-PSA combinations using the reference t-PSA as denominator. Sensitivities, specificities and f/t-PSA cut-offs were calculated for varying points of the ROC curve. RESULTS: Despite good correlation of all 10 f-PSA assays with the reference method 4 showed significantly lower mean f-PSA levels. For f/t-PSA as a predictor of prostate histology, areas under the ROC curve (AUC) varied between 0.65 and 0.71 and, if compared to the reference method (AUC=0.70), were significantly lower in three cases. Ensuring 80% specificity, sensitivities ranged between 34% and 54% (reference method: 53%) and f/t-PSA cutpoints differed considerably depending on the f-PSA assay used (range: 0.15-0.24; reference: 0.15). Similar variations were noted at 95% specificity and 80% and 95% sensitivity. CONCLUSIONS: Arbitrary combinations of f- and t-PSA assays should not be used to calculate f/t-PSA ratios unless adequate studies have validated the diagnostic performance and cut-offs of that particular assay choice.