Prostate Biopsy is Indicated Based on PHI Score
This patient requires prostate biopsy referral based on a Prostate Health Index (PHI) score of 37.7, which exceeds the threshold of 35 that indicates increased risk of clinically significant prostate cancer. 1
Risk Assessment Using PHI
The PHI score of 37.7 places this patient in a higher-risk category that warrants tissue diagnosis:
- PHI >35 significantly increases the probability of detecting high-grade cancer on biopsy, making it a more specific indicator than PSA alone in the 4-10 ng/mL range 1
- The percent free PSA of 15.4% is concerning (below the 25% threshold), which independently supports biopsy consideration 1, 2
- While the total PSA of 4.8 ng/mL falls in the intermediate range where approximately 30-35% of men harbor prostate cancer, the PHI score provides superior discrimination 1
Recommended Biopsy Protocol
Proceed with TRUS-guided prostate biopsy using an extended sampling protocol:
- Obtain a minimum of 8-12 core samples under transrectal ultrasound guidance 3
- Consider multiparametric MRI before biopsy to identify suspicious regions and guide sampling, particularly in elderly patients where precision is critical 1
- Local anesthesia should be offered to minimize discomfort 1
Important Considerations for Elderly Patients
Age-related factors require careful consideration but do not preclude biopsy in this case:
- Men over 75 years should be evaluated individually based on life expectancy and comorbidities, but a clinically significant number present with high-risk cancers that pose substantial risk if undetected 1
- The PHI score's elevation suggests this is not an indolent cancer that can be safely ignored 4, 5
- Consider increasing the PSA threshold for intervention in very elderly men with significant comorbidities, but the current PHI score supersedes age-based hesitation 1
Common Pitfalls to Avoid
Do not repeat PSA testing or defer biopsy based solely on age:
- A single elevated PSA should be verified, but the PHI score already incorporates multiple PSA derivatives (total PSA, free PSA, and p2PSA), providing more robust risk stratification than repeat PSA alone 1, 5
- Avoid using percent free PSA in isolation—the PHI score integrates this information more effectively 1
- Do not order MRI as a substitute for biopsy; MRI is adjunctive and helps guide biopsy technique but does not replace tissue diagnosis 6
If Biopsy is Negative
Should the initial biopsy return negative: