Consistency and Accuracy of 4 Assays for Total and Free PSA in Chinese Population

Core Concepts

PSA assay consistency in Chinese population.

Abstract

Abstract and Introduction

• Lack of interchangeability among PSA assays causes clinical interpretation difficulties.
• Mainstream PSA assays based on Western populations may yield different results in Chinese populations.
• Study compared Beckman, Roche, Abbott, and Mindray assays for tPSA and fPSA levels.
• Predictive accuracy quantified using AUC for each method.

Results

• Roche, Abbott, and Mindray tPSA levels consistent with Beckman, but not fPSA levels.
• Differences in measured values compared to Beckman for tPSA and fPSA levels.
• Diagnostic performance similar among 4 assays at 4 ng/mL tPSA.
• Abbott had the highest missed diagnosis rate at 16% fPSA.

Conclusions

• Mindray, like Roche and Abbott, shows good consistency with Beckman for tPSA.
• Diverse missed diagnosis rates for PCa screening in China with 4 assays using the same %fPSA cut-off.

Introduction

• PSA widely used in PCa screening, monitoring, and response assessment.
• %fPSA can improve specificity in the grey zone of 4-10 ng/mL.
• Inconsistent results among different assays lead to confusion in interpretation.
• WHO calibration aims to minimize variation among different assays.

Overall

• Study compares 4 PSA assays in Chinese population for consistency and accuracy.

Stats

"The measured values were 1.1% higher for Roche, 2.1% higher for Abbott, and 6.7% higher for Mindray compared to Beckman for tPSA levels."
"fPSA levels measured by Roche, Abbott, and Mindray were 5.4% lower, 22.1% higher, and 4.6% higher than Beckman, respectively."
"When the %fPSA was 16%, Abbott had the highest missed diagnosis rate (37.50%)."

Quotes

"When the tPSA level is 2–10 ng/mL, the Mindray, like the Roche and Abbott, has good consistency with the Beckman in detecting tPSA."
"However, 4 assays using the same %fPSA cut-off may lead to diverse missed diagnosis rates for PCa screening in China."

Key Insights Distilled From

Consistency and Accuracy of 4 Assays for Total and Free PSA

by Lingyan Deng at www.medscape.com 04-24-2023

http://www.medscape.com/viewarticle/989697

Deeper Inquiries

How can the inconsistencies among different PSA assays be minimized in clinical practice?

To minimize the inconsistencies among different PSA assays in clinical practice, standardization and calibration are key factors. Utilizing a common calibration standard, such as the WHO calibration, can help align the results obtained from various assays. Manufacturers should adhere to these standards to ensure uniformity in PSA measurements across different platforms. Regular proficiency testing and quality control measures should be implemented to monitor assay performance and accuracy. Additionally, healthcare providers should be aware of the potential variations among assays and consider these factors when interpreting PSA results for patient management.

What are the implications of diverse missed diagnosis rates for PCa screening in China?

Diverse missed diagnosis rates for PCa screening in China can have significant implications on patient outcomes and healthcare resource utilization. Higher missed diagnosis rates can lead to delayed diagnosis and treatment initiation, potentially resulting in disease progression and poorer prognosis for patients. On the other hand, lower missed diagnosis rates can improve early detection and intervention, leading to better outcomes and reduced healthcare costs associated with advanced-stage cancer treatment. Therefore, understanding the impact of diverse missed diagnosis rates is crucial for optimizing PCa screening strategies and improving patient care in China.

How can the %fPSA ratio be optimized to improve diagnostic accuracy in the grey zone of PSA levels?

Optimizing the %fPSA ratio can enhance diagnostic accuracy in the grey zone of PSA levels and aid in distinguishing between benign conditions and prostate cancer. One approach is to adjust the %fPSA cut-off value based on the specific assay used, considering the calibration standard and potential variations among different platforms. Healthcare providers should be aware of the %fPSA ratio's sensitivity and specificity in their clinical setting and tailor the cut-off value accordingly to improve diagnostic accuracy. Additionally, incorporating other biomarkers or imaging modalities in conjunction with %fPSA can further enhance the diagnostic performance in the grey zone, providing a more comprehensive assessment for patients with PSA levels between 4.0–10.0 ng/mL.