Impact of Systematic Biopsy in Detecting Clinically Significant Prostate Cancer

Overview

This single-center retrospective analysis evaluated the diagnostic yield of systematic biopsy (SB), MRI-targeted biopsy (TB), and their combination (CB) in detecting clinically significant prostate cancer (csPCA). The combined approach significantly improved cancer detection rates (CDR) for both overall and clinically significant prostate cancer compared to either method alone.

Background

Prostate cancer diagnosis aims to distinguish clinically nonsignificant (nsPCA) from clinically significant prostate cancer (csPCA) due to differences in prognosis and treatment. Multiparametric MRI with PI-RADS scoring has enhanced csPCA detection, but MRI-targeted biopsy alone may miss some csPCA. Guidelines recommend combining MRI-targeted biopsy with systematic biopsy to improve diagnostic accuracy, though the precise contribution of systematic biopsy remains debated. This study investigates the incremental value of systematic biopsy in initial prostate cancer diagnosis.

Data Highlights

PI-RADS 3–5 dependent CDR for CB: PCA 23.8%, 71.5%, 97.5%; csPCA 16.7%, 64.2%, 96.2%. TB alone detected cancer in 83.3% of patients diagnosed and had lower nsPCA detection (6.8%) than SB (10.8%).

Key Findings

• Prostate cancer was detected in 71.8% of men undergoing combined biopsy, with 65.6% having clinically significant disease (ISUP grade ≥ 2).
• Combined biopsy (CB) showed significantly higher cancer detection rates for both PCA and csPCA compared to targeted biopsy (TB) or systematic biopsy (SB) alone (p < 0.05).
• Systematic biopsy contributed to detecting csPCA missed by MRI-targeted biopsy, supporting its additive diagnostic value.
• Higher PSA density, abnormal digital rectal exam, and suspicious transrectal ultrasound findings were associated with increased detection rates across biopsy methods.
• Targeted biopsy detected less clinically nonsignificant PCA compared to systematic biopsy, though this difference was not statistically significant.
• Adverse events were low, with only 0.8% of patients experiencing urinary tract infections post-biopsy.

Clinical Implications

The combined use of MRI-targeted and systematic biopsy enhances detection of clinically significant prostate cancer, reducing the risk of underdiagnosis inherent to either method alone. Clinicians should consider patient-specific factors such as PSA density and abnormal physical or imaging findings to optimize biopsy strategies. The low complication rate supports the safety of combined biopsy in experienced centers.

Conclusion

Systematic biopsy adds significant diagnostic value to MRI-targeted biopsy by improving detection of clinically significant prostate cancer. Employing a combined biopsy approach is recommended to achieve more accurate tumor grading and guide personalized management.

References

1. University Medical Center Bonn (UKB) 2024 -- The Impact of Systematic Biopsy in Identifying Clinically Significant Prostate Cancer During Primary MRI-Guided Biopsy