Multicentre evaluation of the Boehringer Mannheim/Hitachi 917 analysis system

The new selective access analysis system BM/Hitachi 917 was evaluated in an international multicentre study, mainly according to the ECCLS protocol for the evaluation of analysers in clinical chemistry. Forty-three different analytes, covering 56 different methods enzymes, substrates, electrolytes, specific proteins, drugs and urine applications were tested in seven European clinical chemistry laboratories. Additionally, the practicability of the BM/ Hitachi 917 was tested according to a standardized questionnaire. Within-run CVs (median of 3 days) for enzymes, substrates and electrolytes were <2% except for creatine-kinase MB isoform and lipase at low concentration. For proteins, drugs and urine analytes the within-run CVs were < 4% except for digoxin and albumin in urine. Between-day median CVs were generally < 3% for enzymes, substrates and electrolytes, and < 6% for proteins, drugs and urine analytes, except for lipase, creatine kinase and MB isoform, D-dimer, glycosylated haemoglobin, rheumatoid factors, digoxin, digitoxin, theophylline and albumin in urine in some materials. Linearity was found according to the test specifications or better and there were no relevant effects seen in drift and carry-over testing. The interference results clearly show that also for the BM/Hitachi 917 interference exists sometimes, as could be expected because of the chemistries applied. It is a situation that can be found in equivalent analysers as well. The accuracy is acceptable regarding a 95–105% recovery in standard reference material, with the exception of the creatinine Jaffé method. Most of the 160 method comparisons showed acceptable agreement according to our criteria: enzymes, substrates, urine analytes deviation of slope ± 5%, electrolytes ± 3%, and proteins and drugs ± 10%. The assessment of practicability for 14 groups of attributes resulted in a grading of one–three scores better for the BM/Hitachi 917 than the present laboratory situation. In conclusion, the results of the study showed good analytical performance and confirmed the usefulness of the system as a consolidated workstation in medium-sized to large clinical chemistry laboratories

Some Analytical Considerations on the Measurement of Prostate-Specific Antigen

Peer Reviewe

New developments in the standardization of total prostate-specific antigen

Objective : Analytical evaluation of the calibration of three recently launched assays for the measurement of total prostate-specific antigen, i.e., IMx Total PSA (Abbott), Elecsys PSA (Roche), and IMMULITE 3rd Generation PSA (DPC). Design and methods : For accuracy assessment two reference materials were applied namely, Stanford 90:10 PSA Calibrator and Certified Reference Material 613 Prostate-Specific Antigen. Dilutions of these preparations were analyzed with all assays. In addition, clinical specimens from known prostate cancer or benign prostate hyperplasia patients and samples taken from an ongoing prostate cancer screening study were used for comparison. Results : Application of the Stanford Calibrator revealed results well within 10% of the calculated values for all assays. Regarding the CRM Calibrator only the IMx Total PSA proved to approach the line of identity. The IMMULITE results differed about 40% and the Elecsys about 18% from the calculated values. The comparison with clinical specimens showed statistically different results for the combination IMMULITE-IMx and for IMMULITE-Elecsys. The regression lines for both collections were: y(IMx) = 0.86x (IMMULITE) + 0.12 (n = 104, r = 0.970, S(y/x) = 0.883 μg/L) and y(Elecsys) = 0.98x(IMMULITE) + 0.38 (n = 97, r = 0.976, S(y/x) = 0.733 μg/L). In the lower measuring range (PSA < 5.0 μg/L) as measured with the screening samples (n = 43), these differences were less pronounced. Conclusion : In analytical sense a difference was found for both reference preparations in the assays studied. Clinically, despite improvements in methodology, results for total prostate-specific antigen are still not interchangeable. The possible consequences need to be elaborated

Screening for prostate cancer:results of the Rotterdam section of the European randomized study of screening for prostate cancer

BACKGROUND: Evidence from randomized trials on the effects of screening for prostate cancer (PCa) on disease-specific mortality accumulates slowly with increasing follow-up.OBJECTIVE: To assess data on PCa-specific mortality in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial.DESIGN, SETTING, AND PARTICIPANTS: A randomized controlled trial with randomization after signed, written informed consent (efficacy trial). In the period 1993-1999, a total of 42 376 men aged 54-74 yr were randomized to a screening arm (S-arm) (n = 21 210 with screening every 4 yr, applying a total prostate-specific antigen [PSA] level cut-off ≥ 3.0 ng/ml as biopsy indication) or a control arm (C-arm) (n = 21 166; no intervention).OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Number of PCas detected per arm depicted by predefined time periods and prognostic groups. PCa-specific mortality analyses using Poisson regression in age group 55-74 yr at randomization and separately in the predefined age group of 55-69 yr.RESULTS AND LIMITATIONS: After a median follow-up of 12.8 yr, 19 765 men (94.2%) were screened at least once and 2674 PCas were detected (of which 561 [21.0%] were interval PCas). In the C-arm, 1430 PCas were detected, resulting in an excess incidence of 59 PCas per 1000 men randomized (61 PCas per 1000 in age group 55-69 yr). Thirty-two percent of all men randomized have died. PCa-specific mortality relative-risk (RR) reductions of 20.0% overall (age: 55-74 yr; p = 0.042) and 31.6% (age: 55-69 yr; p = 0.004) were found. A 14.1% increase was found in men aged 70-74 yr (not statistically significant). Absolute PCa mortality was 1.8 per 1000 men randomized (2.6 per 1000 men randomized in age group 55-69 yr). The number needed to invite and number needed to manage were 565 and 33, respectively, for age group 55-74 yr, and 392 and 24, respectively, for age group 65-69 yr. Given the slow natural history of the disease, follow-up might be too short.CONCLUSIONS: Systematic PSA-based screening reduced PCa-specific mortality by 32% in the age range of 55-69 yr. The roughly twofold higher incidence in the S-arm underlines the importance of tools to better identify those men who would benefit from screening.</p

Screening for prostate cancer:results of the Rotterdam section of the European randomized study of screening for prostate cancer

BACKGROUND: Evidence from randomized trials on the effects of screening for prostate cancer (PCa) on disease-specific mortality accumulates slowly with increasing follow-up. OBJECTIVE: To assess data on PCa-specific mortality in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial. DESIGN, SETTING, AND PARTICIPANTS: A randomized controlled trial with randomization after signed, written informed consent (efficacy trial). In the period 1993-1999, a total of 42 376 men aged 54-74 yr were randomized to a screening arm (S-arm) (n = 21 210 with screening every 4 yr, applying a total prostate-specific antigen [PSA] level cut-off ≥ 3.0 ng/ml as biopsy indication) or a control arm (C-arm) (n = 21 166; no intervention). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Number of PCas detected per arm depicted by predefined time periods and prognostic groups. PCa-specific mortality analyses using Poisson regression in age group 55-74 yr at randomization and separately in the predefined age group of 55-69 yr. RESULTS AND LIMITATIONS: After a median follow-up of 12.8 yr, 19 765 men (94.2%) were screened at least once and 2674 PCas were detected (of which 561 [21.0%] were interval PCas). In the C-arm, 1430 PCas were detected, resulting in an excess incidence of 59 PCas per 1000 men randomized (61 PCas per 1000 in age group 55-69 yr). Thirty-two percent of all men randomized have died. PCa-specific mortality relative-risk (RR) reductions of 20.0% overall (age: 55-74 yr; p = 0.042) and 31.6% (age: 55-69 yr; p = 0.004) were found. A 14.1% increase was found in men aged 70-74 yr (not statistically significant). Absolute PCa mortality was 1.8 per 1000 men randomized (2.6 per 1000 men randomized in age group 55-69 yr). The number needed to invite and number needed to manage were 565 and 33, respectively, for age group 55-74 yr, and 392 and 24, respectively, for age group 65-69 yr. Given the slow natural history of the disease, follow-up might be too short. CONCLUSIONS: Systematic PSA-based screening reduced PCa-specific mortality by 32% in the age range of 55-69 yr. The roughly twofold higher incidence in the S-arm underlines the importance of tools to better identify those men who would benefit from screening

Multicentre evaluation of the Boehringer Mannheim/Hitachi 917 analysis system

The new selective access analysis system BM/Hitachi 917 was evaluated in an international multicentre study, mainly according to the ECCLS protocol for the evaluation of analysers in clinical chemistry. Forty-three different analytes, covering 56 different methods-enzymes, substrates, electrolytes, specific proteins, drugs and urine applications-were tested in seven European clinical chemistry laboratories. Additionally, the practicability of the BMI Hitachi 917 was tested according to a standardized questionnaire. Within-run CVs (median of 3 days) for enzymes, substrates and electrolytes were <2% except for creatine-kinase MB isoform and lipase at low concentration. For proteins, drugs and urine analytes the within-run CVs were <4% except for digoxin and albumin in urine. Between-day median CV's were generally <3% for enzymes, substrates and electrolytes, and <6% for proteins, drugs and urine analytes except for lipase, creatine kinase and IMB isoform, D-dimer, glycosylated haemoglobin, rheumatoid factors, digoxin, digitoxin, theophylline and albumin in urine in some materials. Linearity was found according to the test specifications or better and there were no relevant effects seen in drift and carryover. testing. The interference results clearly show that also for the BM/Hitachi 917 interference exists sometimes, as could be expected because of the chemistries applied. It is a situation that can be Sound in equivalent analysers as well. The accuracy is acceptable, regarding a 95-105% recovery in standard reference material, with the exception of the creatinine Jaffe' method. Most of the 160 method comparisons showed acceptable agreement according to our criteria: enzymes substrates, urine analytes deviation of slope +/-5%, electrolytes +/-3%; and proteins and drugs +/-10%. The assessment of practicability for 14 groups of attributes resulted in a grading of one-three scores better for the BM/Hitachi 917 than the present laboratory situation. In conclusion, the results of the study showed good analytical performance and confirmed the usefulness of the system as a consolidated workstation in medium-sized to large clinical chemistry laboratories

Screening and prostate-cancer mortality in a randomized European study

BACKGROUND: The European Randomized Study of Screening for Prostate Cancer was initiated in the early 1990s to evaluate the effect of screening with prostate-specific-antigen (PSA) testing on death rates from prostate cancer. METHODS: We identified 182,000 men between the ages of 50 and 74 years through registries in seven European countries for inclusion in our study. The men were randomly assigned to a group that was offered PSA screening at an average of once every 4 years or to a control group that did not receive such screening. The predefined core age group for this study included 162,243 men between the ages of 55 and 69 years. The primary outcome was the rate of death from prostate cancer. Mortality follow-up was identical for the two study groups and ended on December 31, 2006. RESULTS: In the screening group, 82% of men accepted at least one offer of screening. During a median follow-up of 9 years, the cumulative incidence of prostate cancer was 8.2% in the screening group and 4.8% in the control group. The rate ratio for death from prostate cancer in the screening group, as compared with the control group, was 0.80 (95% confidence interval [CI], 0.65 to 0.98; adjusted P=0.04). The absolute risk difference was 0.71 death per 1000 men. This means that 1410 men would need to be screened and 48 additional cases of prostate cancer would need to be treated to prevent one death from prostate cancer. The analysis of men who were actually screened during the first round (excluding subjects with noncompliance) provided a rate ratio for death from prostate cancer of 0.73 (95% CI, 0.56 to 0.90). CONCLUSIONS: PSA-based screening reduced the rate of death from prostate cancer by 20% but was associated with a high risk of overdiagnosis. (Current Controlled Trials number, ISRCTN49127736.