What are the implications of Total PSA 2.89 and Free PSA 0.729 on Silofast D8 (Silodosin)?

PSA Interpretation on Silodosin Therapy

Your PSA values are reassuring and do not require immediate intervention, but warrant continued annual monitoring given your free-to-total PSA ratio of 25.2%. 1, 2

Understanding Your PSA Results

Your current values show:

• Total PSA: 2.89 ng/mL (below the 4.0 ng/mL threshold that typically triggers biopsy consideration) 3, 2
• Free PSA: 0.729 ng/mL
• Free-to-total PSA ratio: 25.2% (0.729/2.89 = 0.252 or 25.2%)

This ratio is particularly important because a free PSA percentage >25% indicates lower cancer probability and suggests benign disease, while percentages <10% indicate higher cancer risk requiring biopsy. 3, 1, 4

Effect of Silodosin on PSA

Alpha-blockers like silodosin (Silofast D8) do NOT significantly affect PSA levels, unlike 5-alpha reductase inhibitors (finasteride/dutasteride) which reduce PSA by approximately 50%. 3, 2 Therefore, your PSA values can be interpreted at face value without any adjustment factor.

Clinical Significance and Risk Stratification

Your free PSA percentage of 25.2% places you in a lower-risk category:

• At a 25% cutoff, 95% of prostate cancers can be detected while avoiding 20% of unnecessary biopsies 1, 4
• Men with total PSA 2-4 ng/mL have a 15-25% likelihood of biopsy-detectable prostate cancer, but your favorable free PSA ratio reduces this concern 3
• Research shows that men with PSA ≥2 ng/mL and free PSA >25% have only 0.03% cumulative incidence of fatal prostate cancer at 15 years 5

Recommended Management Algorithm

Follow this structured approach:

1. Continue annual PSA monitoring with DRE (digital rectal examination) every 6-12 months 1, 2

2. Calculate PSA velocity at each visit using at least 3 measurements over 18-24 months 3:

   • Concerning velocity: >0.75 ng/mL/year for PSA 4-10 ng/mL range 3, 4
   • For PSA <4 ng/mL: >0.35-0.4 ng/mL/year warrants closer attention 3

3. Trigger biopsy consideration if ANY of the following occur:

   • Total PSA rises above 4.0 ng/mL 2, 4
   • Free PSA percentage drops below 10% 3, 4
   • PSA velocity exceeds thresholds above 3, 2
   • Any abnormality on DRE (nodule, asymmetry, firmness) 2
   • Sustained PSA rise from current nadir value 3

4. Use the same PSA assay for all future measurements, as different assays are not interchangeable and lack acknowledged conversion factors 3, 2

Critical Pitfalls to Avoid

• Don't assume your "normal" total PSA eliminates cancer risk entirely - men with PSA <4 ng/mL can still harbor prostate cancer, though your favorable free PSA ratio is reassuring 3, 5

• Don't test PSA during active urinary tract infections or within 2 weeks of prostate manipulation, as these can artificially elevate values 2

• Don't ignore PSA velocity even if absolute values remain "normal" - rapidly rising PSA with normal absolute values can indicate aggressive cancer 2, 4

• Avoid testing immediately after ejaculation or vigorous physical activity, which can transiently elevate PSA 2

When to Escalate Care

Immediate urology referral is warranted if:

• PSA velocity ≥1.0 ng/mL per year 2
• Any palpable abnormality on DRE 2
• Free PSA percentage drops to ≤10% 4
• Total PSA exceeds 4.0 ng/mL on repeat testing 2

Your current values with 1 year of stable therapy suggest benign prostatic hyperplasia rather than malignancy, but the key is longitudinal monitoring to detect any concerning trends early. 1, 5